In theory, you can even compile extensions for ActiveState Perl with the toolchain provided by Strawberry Perl

Not only in theory, but in practice too !!
I think that Corion's suggestion of using MinGW and dmake (which is what he means by the "toolchain provided by Strawberry Perl") is a good one. Whether you use that toolchain with Strawberry Perl or with ActiveState Perl shouldn't make any difference.

Until someone provides a ppm package of DBD::Oracle (which, afaict, hasn't yet happened re perl-5.10.0), you'll have to build it yourself. Give it a go with dmake and MinGW - report the errors you encounter, and someone will possibly be able to help you proceed.

Cheers,
Rob