This helpful, if disclaimer-rich, page on the Motorola website is uncharacteristically open about the option to hack your Motorola DVR and get the video from it to a PC:
...but some people on their own have devised a way to access digital recordings on the DCT6208 or DCT6412 and offload them to a PC hard drive or Digital High Def VCR... Here's how to transfer non-copy protected recordings via IEEE1394/Firewire...
I wish all manufacturers were so open an honest about the hackability of their products. The DCT6412 (or is it the 6408?), by the way, is the DVR that [[Eastlink]] offers here in Prince Edward Island for $14.95/month.
Here's how to do much the same thing with a Mac.