Sony announced late last week that the PSP Comics Store was going to stop selling digital comics at the end of October. Previous purchases will still be available for the next several months, but the service will completely shut down in January 2013. They're also noting that you can still download and back up your purchases onto a PSP as well as the Media Go Windows app.
This move does not come as a surprise. Sony has long since stopped updating the service, and they formally stopped development in July 2011. While they have been continuing to add content from comics publishers like Dark Horse, Marvel, and others, there was never any new news on expanding the service to other devices or adding new features. In fact, a brief Google search indicates that Sony never did launch this service on the PS Vita.
Sony originally launched the PSP Comics Store in late 2009, and I was impressed with it when i saw it at CES 2010 a few months later. But like many of Sony projects, support from above seems to be hit or miss. Today it looks like it's going to be a miss.
This does not bode well for the Sony Reader, does it? I seriously doubt that Sony is earning any significant income on the PRS-T2 ereader or content sold for it, so I would not be surprised to learn that Sony next plans to cast off their ebook service as well.
Their enthusiasm for ebooks is already lackluster; look at how few improvements the PRS-T2 got when it was launched a couple months ago. It's basically little more than a less capable PRS-T1 in a new shell. That makes it little more than a placeholder for the market, not a sign of significant interest.