I really should revive the Sluice project. Keyword filtering and setting aside items are two of the most concrete intended features (alongside de-duplication and same-link post stacking).
I have to admit I was interested in exploring the social side with my app as well, so I'm glad Google made that mistake before I did. =^)
I just want a way to manage my river of news so that the can't-miss items aren't missed, and the always-skip items are skipped, and above all I should never be blithely offered the same exact link with the same exact metadata more than once. Everything beyond that is negotiable.
I have 4GB system and 512GB video memory installed. However, I only upgraded from 2GB after installation because the already-heavy Java apps I use (Eclipse, SQL developer) now required twice the memory.
As the other commenter mentioned, there are the CPU optimizations to consider, but what decided my final transition (I've tried it out a few times over the past few years) was when System76 moved to shipping their systems with the 64-bit distro installed. I want to maximize their ability to support me, so when I did a fresh install on a new drive I opted for 64-bit as well.
Most of the problems of compatibility with 32-bit binaries have been trivialized or are routed around easily enough these days. Though 64-bit Linux was never as much hassle as x64 Windows. ;^)
I use a few packages from http://www.getdeb.net/ and have several PPAs https://launchpad.net/ubuntu/+ppas installed as well so there's some secondary lag there as those developers release new packages for 9.10. Which shouldn't be too long, really.
My main concern with this release is the ongoing, phantom ext4 (and sometimes 3?) corruption problem. Depending on which reports you read, it affects 64-bit installations specifically, which is what I use.
As much as the software, I want to ensure that there's plenty of community documentation and collective experience compiled before I switch. My System76 laptop here is my bread and butter; I don't want to find myself pathfinding on a new problem when I need to get things done, I want someone to have already charted a solution.
Looking forward to upgrading from 9.04 to 9.10 ...in 3 to 6 months when all the bugs are shaken out and everything is compatible with the new version. =^)