Interesting data about mobile checkout apps:
The cost of merchant's mobile app:
    $7,000 on average, with more comprehensive applications costing $150,000 and more.
    By 2017, retailers believe that over 50% of sales transactions will come from a mobile device self-checkout.

Cartes (Exhibition & Conference) in Paris, France next week... Well, maybe Cartes America in Las Vegas next year...

PCI SSC has released a document that "highlights anticipated changes to the PCI Data Security Standard (PCI DSS) and Payment Application-Data Security Standard (PA-DSS) in order to prepare organizations for the introduction of Version 3.0 in November 2013".
I could not find any significant changes that would help to improve the security of card payment transactions. I wasn't surprised though.

Biometric scanner on mobile phone is interesting feature that might be helpful to enhance security of mobile payments, as well as simplify the payment process and reduce the transaction processing time.

The company offers online payment technology using credit cards, which they call "two-click email checkout". Apparently, no American Express (or any method other than Visa, MasterCard, and Discover) is supported. I don't see anything specific to mobile payments though. It looks like this is another online payment API which can be integrated with (online) merchant's website for processing payments on its webpages, regardless of whether those pages are rendered on PC, tablet, or iPhone screen. I am not sure how and if it is different from other established online payment systems, which at least we can trust, such as PayPal or Amazon Payments - maybe by the number of clicks? 

I just published the Mobile Checkout - secure mobile payments solution proposal which I created (along with the working proof of concept) back in 2009. 
Compare it with Starbucks Mobile App - can you see any similarity? (No, I have never sent this proposal to Starbucks... Unfortunately... )
However, there is a big difference as well: in my solution, the card number was not displayed on the mobile phone screen as it is done in Starbucks app (xxxxxxxxxxxx9189 in the screenshot below). My app was displaying just 4 digits - simple randomly generated token (4067 in the screenshot below) which becomes useless as soon as the barcode is scanned (or the 4 digits are keyed) by cashier and the mobile device is linked with the point of sale transaction. The actual payment card number was never exposed  to the mobile device and point of sale because the transaction was processed in a cloud between mobile app and point of sale servers.

The popular Costa Rica based online payment system Liberty Reserve went down following the arrest of his founder Arthur Budovsky (Артур Будовский). Budovsky, 39, a former U.S. citizen and naturalized Costa Rican of Ukrainian origin, was arrested in Spain as part of a money laundering investigation. 
I found interesting U.S. Department of Justice report about money laundering in digital currencies. In addition to information about the money laundering payment systems, it explains in an accessible form the methods of anonymous Internet access: 
Various technologies can increase the utility of digital currencies for money laundering by providing additional anonymity and networking abilities. Because digital currency transactions are conducted over the Internet, they can be traced back to individuals’ computers. The origins of Internet activity can often be identified using IP (Internet Protocol) addresses. Each computer on a network, including the Internet, must be uniquely identified by an IP address in order to receive information, such as web pages, requested from remote servers. These servers, including digital currency servers, track and record users’ IP addresses.
However, anonymizing proxy servers and anonymity networks protect individuals’ identities by obscuring the unique IP (Internet Protocol) address as well as the individuals’ true locations. Anonymizing proxy servers and anonymity networks are designed to prevent identification of Internet users’ IP addresses. Such proxy servers and networks redirect users’ activities so that they appear to originate from a proxy server’s or anonymity network’s IP address rather than the IP address of an individual Internet user. 
Furthermore, mobile payments conducted from anonymous prepaid cellular devices, such as web-enabled phones, may be impossible to trace to an individual. Such portable devices that provide Internet access enable transfers of digital currency; afterward, they can be destroyed, easily and inexpensively, to prevent forensic analysis. 

Does it only happen to me? Are they serious?
Thanks to Apple online store which worked just well - under the same stress.

This guy -- ZonD Eighty -- managed to trick the Apple app store payment system (by using the alternative payment website -- in-appstore.com -- and fake certificates) in order to get for free the services which are normally supposed to be paid through the Apple app store. Here is how it works (pretty simple!):

"First
Sign off your appleID in Settings->Store->Tap on your appleid->Sign Off

Second
Open this page into your iDevice. Install these certificates (just tap on links): First, Second. The order of installing is very important! Install first certificate first, second - second.

Third
Go to application where you want to buy in-apps, and make attempt to buy something. Tap "Cancel" on "Do you really want to purchase?" window.

Fourth
Open Wi-Fi settings on your iDevice and tap arrow on the right of your Wi-Fi network. Remove all data from DNS field and set it to this IP address: 94.228.221.10, 91.224.160.136(more to come)

U're done!Go to your application and try to buy something!" 

PayPal's 'pay by mobile' application does not use NFC. Instead, it generates and shows the code which can be read (and keyed) by cashier or POS scanner. I suggested this technology 3 years ago. It was wrong time and... wrong place.

Video from PayPal: 
http://bit.ly/L3KGwE
Video with my solution:
http://bit.ly/LgBvp6
iPhone app:
http://bit.ly/JNvCUR
Android app:
http://bit.ly/LU1DIl