Hallo!
Official repository don't provide puredata. Old version (0.39) could be found in Etch repository.
Yes an old version is also in the Xandros repositories ... However, I also compiled pd from source now.
And it really runs quite nice - one of my performance patches with arduino interface uses about 20% (some synths, samples and effects) and also without dropouts when switching windows etc. However, I didn't test the latency so far ...
So it's really nice for simple audio things, especially if you have some other interfaces and don't want to show your big computer ... ;)
LG Georg