Yes, they've made it so you can order the HD transfer cable for free. You just need the serial numbers of both systems.
http://assets.xbox.com/en-us/support/MigrationKit-OrderForm.pdf
Just to add my experience here, bought a 360 used, fully working. It was an Oct 2005 unit, if I'm not mistaken. It worked just fine up until a few months ago, then suddenly 3 rings.
Even though it was a 2005 unit, M$ denied ever making the offer to fix 2005 units, and later that yes, they had fixed them, but they had conveniently stopped that program less than a month before mine failed.
After having dealt with an original xbox failure to the tune of 3 months of calls, bitching, and lies from the "CSR"s; and knowing that even if I shelled out the $140 for repair, the warranty was only 90 days, I decided to sell my broken one on CL and buy a core. Irony of ironies, the core I ended up with (bought it at a closing CompUSA, so no returns) was a Feb 06. How they still had units from that date in March of 2007? I haven't a clue. Probably why they closed. I wish I would have noticed before I checked out. In any case, my credit card will cover it for an additional year, so hopefully that'll work.
Less than two weeks later? They extended the repair warranty to a year. I'm genuinely surprised they *haven't* been more raked over the coals about this, but it's likely difficult if not impossible to get real repair numbers, considering it's all internal.