Features I'm working on right now:

1) New theme, something lightweight, and more like the phpspeed.com site theme.

2) Main (index.php) page is the 'stats' page and require login to run tests and view server stats, that way you can share the link freely with others for comparison (need to decide what type of login is best)

3) Better previous test output

4) Import capability for comparison between two servers with graphs, etc...

The current theme is already pretty lightweight,  I wouldn't worry too much about that.  I could help clean it up a bit--a little CSS here, and a little XHTML there.

One thing that jumped out at me: at the end of each test, it should say what the results of the previous test(s) were, and then maybe show the average as well. Instead of having to click to view the results.   Some graphs would be helpful too.  Instead of giving directions on how to interpret data, maybe the tool could detect and the throw away the statistical outliers and give some context -- like, "omg your server is crap, get a new host or try some optimization techniques."  I think the arrangement of the right-hand sidebar is not prioritized correctly, the last thing I want to see is "server time"  and version info.  However, the dynamic scorecard (which I'm still a little fuzzy on) seems important enough to be moved up to the top.

Get a pi calculator too, I heard many machines intent to use pi calculation to test CPU's power.
I have developed a pretty fast pi calculator in PHP that find 2000th place of pi in 4 seconds. of course, you have to have BCmath extension.

Sounds cool mgccl.  Currently our focus is on php and server subsystems, but I can see doing some cpu specific testing in the future.