heh, the solution was totally easy.. you had some stuff in the uc_optional_checkout_review_form_submit function that built a paypal_wps form and then submitted it.. well exactly the same stuff can be done for adyen as well.. I wonder if there is a way of making that work in a more generic fashion, for many more payment methods?

Either way, thumbs up for the module! You should really get it posted on drupal.org to get the more exposure and help from the community. If you want, I can help you with that, got a CVS account and all, wouldn't mind helping with maintenance either. Drop me a line if interested.

Cheers