As far as running interpreted languages goes,
I already have Hot Paw Basic running on my Palm 7x.
So obviously even a very limited implementation would be possible.
The issue is more one of SIZE, since we're talking about 8Mb TOTAL,
including whatever scripts you want to run.
Codewarrior is available for Palm to build C apps. (?C++?)
Since a lot of PERL is written in C, it would seem that it would be POSSIBLE.
But it also seems like it would be a lot of frustration. Looking at the footprint that
PERL takes up on my workstation, storage-wise, with modules & all I think the real problem
will be storage space.
In this I think PocketPC's will have PERL long before Palm ever does.