I am hoping that payment processing will support Moneris as a payment processing partner in addition to PayPal, etc. Specs are available at https://www3.moneris.com/connect/en/documents/index.html, with details for php available at https://www3.moneris.com/connect/en/download/feb05/PHP/PHP_integration_guide_wVbV.pdf and for Verified by Visa processing at https://www3.moneris.com/connect/en/download/feb05/PHP/PHP_VBV_integration_guide.pdf. Note that they support recurring transactions, which is important for regular monthly giving to non-profits.
Also IATs processing integration would be helpful.
http://www.iats.ticketmaster.com/english/index.html
For reference - moneris has been in core for a few years now, and IATS should be in 2.0. If you want to try out IATS for versions before 2.0 (but after 1.6) see:
http://homeofficekernel.blogspot.com/2007/12/iats-and-civicrm.html