Shouldn't we then provide a cygperl5_8.dll symlinked to cygperl5_8_5.dll also (in linux fashion), and apps should link against cygperl5_8.dll resp. a more generic libperl.dll.a then? otherwise you'll have to recompile all dependent apps.
You are forgetting something. The Windows runtime linker (understandably) doesn't understand Cygwin symlinks. From what I've heard, perl tries to stay ABI-compatible throughout x.y.*, so the DLL should be named cygperl5_8.dll
Max.