Including very important ones, like "can I keep my old friends page?".
The answer to that question is buried in the comments, and appears to be "no". See this comment: "Once the new friends feed is out of Beta testing, it will no longer be possible to switch back to using other style-based friends pages like there are now.".
To be slightly fair, the reasoning they give makes some sense - the sheer number of different styles is making it hard for them to add new features (apparently the repost feature resulted in confusion because some themes didn't show who made the repost). This is all very well, but the reason there are lots of different styles is because people like customizing their journal. The new feed currently has an unknown level of customisation (they say "at least text size and background images", but that's a far cry from what the built-in themes let you do, let alone what's possible if you write your own theme).
It doesn't help their case that the new feed is also missing several features. There's no sign of a custom page title, friend colours, mood icons, the link bar, or custom comment labels - all of which are things that the friends page has had since at least 2004. I've also found three bugs in how posts are shown (long links are cut off by the right-hand margin, some RSS feeds are full of extra line breaks, and the "Up" button disappears off the right-hand side of the screen). Wait, make that four bugs: the layout is too wide for a 1024x768 screen. That makes it the only site I use frequently that doesn't fit in a 1024x768 window (even deviantart works in that!), and also makes it unusable for me.