I already pulled in the dashCommerce code into 2008 and managed to work out the bugs. Like, all the references to old dlls. So, I just pulled in the Authorize.net payment provider, and I'm receiving this error message when I attempt to configure it.
A critical error has occurred: Could not load
file or assembly 'AjaxControlToolkit, Version=1.0.10301.0,
Culture=neutral, PublicKeyToken=28f01b0e84b6d53e' or one of its
dependencies. The located assembly's manifest definition does not match
the assembly reference. (Exception from HRESULT: 0x80131040)
Am I going to be able to use this provider in 2008? I don't think so, unless they redistribute it using the latest version. They must have references the old version when creating that control.