in the N900's internal browser i think we currently have flash 9.0,246,0
in easy debians precompiled image u get 9.0,48,0 while running the web browser Ice Weasel (firefox based) (atleast in the precompiled image i got).

if we are lucky that means that it would be possible to make a hack for manual upgrade to upcoming flash versions (but hardware acceleration may be tricky in flash 10 unless were lucky).

in case it really turns out that nokia and adobe really abandon the plans for flash 10.1 on debian (ARM version) or the n900, we will be dependent on such hacks - alternatively if the Meego project turns out so well that we'll get all fedora (ARM version) possibilities and its web browsers with flash if it supports N900 hardware... should do so as long as its arm cortex a8+sgx535 based