When I learned about how it worked one or two nights ago, I went and dug up all of my various battle chest or individual cd keys, and had no issues whatsoever.
I was able to register all supported games, even with an international cd key or two, and assign myself English (US) versions as downloads. Pre-patched and no cds required, going forward.
The cd keys will even be stored in your account, for future access (and older keys with less digits are upgraded to the "full" cd keys we see today, IIRC).
Hell, from what I've read, you basically have unlimited, unfettered, DRM-free access to these downloadables forever.
Brilliant.