I have Lion, running on a 64 bit kernel
$ uname -a
Darwin dyn1158-144.insecure.ic.ac.uk 11.4.0 Darwin Kernel Version 11.4.0: Mon Apr 9 19:32:15 PDT 2012; root:xnu-1699.26.8~1/RELEASE_X86_64 x86_64
but I have a number of 32 bit apps (among which, to my surprise, Google Chrome) that run perfectly fine.
I am not overly concerned about Chrome, but there are a few things I'd loathe to lose, either because they cost me money (Photoshop CS3, which should actually work), or because I like then (Luna menu, RapidoSerial, which are not on RoaringApps).
Is there a final yes/no answer to the question, will a generic 32 bit intel app run on ML?