It seems others are also interested in using the Raspberry Pi. I have mine up and running. I've even got BOINC installed on it. Unfortunately there are no projects currently supporting it at the moment.
You have to remember the Pi only has 256Mb of main memory. Mine has 70Mb free when running BOINC, so if the science apps can fit in that then they should run. Its not that fast, so you'd want something that isn't too complex for it to run. I have been looking at the Seti Multi-beam app, which might just squeeze in. There isn't one in the repo, so I have to get the source and compile it myself.
If people ask their favorite projects for science apps they may look into it (Asteriods @ Home has said they will) assuming the hardware isn't too limiting. That means there is no point in asking over at CPDN as their climate models are huge and take a long time to process. Look for an existing message thread or start a new message thread on the project message boards to get the ball rolling. If enough people ask then the projects are more likely to do something. If projects are supportive we can get native BOINC support rather than needing to use an app_info file (also known as the anonymous platform mechanism).
Its possible to run the Pi in command line mode (ie not run X-Windows on it) which should free up a bit of memory. Exactly how much I don't know. Terminal (the program) seems to use 91Mb, which seems rather excessive. Not running it should also free up some memory.
Where do you get it?
The other question I have been asked is where I got mine from. Well I ordered two. The Raspberry Pi website has two suppliers listed. I ordered one from the 2nd link (Allied Electronics and RS Components) and after ordering found out its on back-order for up to 13 weeks. After that I went to the other site (Element 14) who have a local presence here in Sydney, Australia and they had 800 in stock. It arrived about 2 days after ordering, with the case being delayed by a week.