Well, they lost a paying customer out of me. Way to fail Ubisoft.
There is really no point in going beyond a simple CD key. Anyone that downloads a crack for a CD key, can just as easily download a crack for a more complex system like AC2 ( The pirated version will probably just save the game to your own computer, which means pirates will be getting the better end of things. )
I disagree only slightly on best DRM measure being to lower prices...for me the best DRM is being an awesome studio, always producing extremely high quality games that are actually worth that cost, etc....for me, the only company that currently sits there though is Bioware. I gladly bought the CE for both DA and ME2, more out of support for Bioware than anything else...and I can't wait for SW:TOR.