Sony is currently working on a visual redesign of PlayStation Network. The makeover will place PSN more in line with Steam and Xbox Live as opposed to its current text-heavy style. It seems that these changes would affect the PlayStation Store rather than the main XMB.
Sony is trying to de-clutter the service in favour of "an aesthetic layout with logically marked sections and rolodex lists". New features include; live search that shows more results and a database-like listings for both games and movies, showing details like developers or cast members. The blue background will also be replaced by a black one, with brighter colours highlighting content.
A 'deal of the week' section will also be added. It doesn't sound like anything exciting, though a new paintjob is never a bad thing. Sony has messed around with the Store before. There are a number of possible reasons for Sony's decision to give the Store an overhaul like trying to regain some of the trust that the service lost when it was hacked two months ago by going for an image change.