The compatibility list of phones/devices is slowly being established as people are experimenting with phones from other carriers. The HSPA devices that TELUS sells are guaranteed to work on the new network (obviously). If you have a particular phone in mind then call TELUS and they may, and I stress may, be able to tell you if it is compatible or not. Keep in mind that they couldn't care less if a device from another carrier will be compatible or not.
Also, if you are a current CDMA client then you must convert your contract to the new HSPA network which will allow you to keep your existing plan in most cases.