I like the fact that Outlook 2007 has RSS support built in but right now, at least in Beta 2, it feels like an afterthought. I made the mistake of importing over 100 RSS feeds into Outlook and suffered through quite a bit of problems getting rid of all the feeds once I discovered how slow the interface is.
Even though I've deleted them in Outlook, and deleted them in the IE 7 RSS feed area, I keep getting the ghost of RSS Feed's past on my Exchange 2003 account. I can't seem to purge them completely.
On my laptop running XP Pro, if I have Exchange cache-mode enabled with Outlook 2007, once I have sync'd with the home office, it will get stuck in an infinite loop of crashes and restarts which has resulted in many error reports being sent off to Microsoft. My home computer, which is running an interim release of Vista (post Beta 2 / pre RC1), does not crash with the same settings and build of Outlook 2007. I'm not quite sure what is 'invalid' on my laptop and/or Exchange account that kills Outlook under XP but if I disable cached-mode, Outlook stops crashing.
After one of the crashes, some of my deleted, and what I thought were purged old RSS feeds, ended up attached to the root folder of my Exchange mailbox, which was pretty strange. I've cleaned that up again and I'm halfway tempted to recreate my mailbox the dirty way by moving it from one information store to another, to see if that fixes the problem.
One thing I really would like with the RSS feed is the ability to right click on the 'RSS feed' folder and be able to select 'Mark all as read' and have that apply to all the RSS feeds subscribed. Right now, there is a 'Mark all as read' option but it currently does nothing.
So, for now, I'm back to Mozilla Thunderbird nightly builds as my default RSS feed reader of choice. It might not be pretty and it might not have all the features of the other readers, but it at least seems to scale well with hundreds of RSS feeds. I guess I must confess to being an information junkie.
Everything else about Outlook 2007 is pretty nice I must admit, so this is honestly just a minor gripe.