According to The Official Nintendo Magazine, the tweaked Wii will be released in the UK this holiday season (no word about a US release).
The change is that this Wii is designed to lay flat and has a slighted refigured design. The original Wii was supposed to sit vertically.
The redesigned console comes packed with a Wii Remote Plus, a Nunchuk and, according to this photo from Eurogamer, copies of Wii Sports and Wii Party.
Expect more details like pricing and non-UK availability.