The three most exciting features in that list (for me) would be the homebrew widgets, enabling personalised feeds (rss maybe??) and features; the open file transfer system, it could be a new means to save file transfers and other media on the user's hdd
and the xmb music system - listen to music from the hdd while using the browser! i would like someone to explain the reason behind not being able to keep a track playing while performing another task (such as web browsing or testing the internet connection or woteva you wana do)
something else caught my attention too - a system hosting a service if traffic is an issue to allow video/audio streaming over a network
just seems like such an interesting idea