Andrew,
Probably in a lot of cases yes however the least you have to do is change
the extention name from asp to aspx. Used in the classic asp way there is
not so much difference between classic asp and aspnet without compiled
Dll's.
It is possible to go step by step from asp to aspnet, as well without
compiled Dll where one of the advantage is the more readability of your
code.
(Seperation of the serverside code from your HTML)
The best newsgroup for more information about your question is probably
microsoft.public.dotnet.framework.aspnet
I hope this helps?
Cor