According to Digitimes, Nintendo is going to ship Wiis with updated circuitry that is aimed at blocking the use of modchips. It also reports that, “new-generation modchips capable of working with the revised Wii consoles may become available in less than a month, according to retail channels in Taiwan.

"The new Wiis, which are part of new shipments of the console, have an altered circuit layout that makes modification more difficult than in earlier versions. Users attempting to mod the new consoles using current modchips are very likely to damage the system, the sources pointed out."

The report details expectations for the integrated circuits as follows, “Nintendo could adopt BGA (ball grid array) IC packaging to prolong the time needed by hackers to develop new modchips to at least four months.”
As yet there is no official word from the UK on when or if the new Wiis will hit our shores.

^Digitimes