Cannibals, i think Guy just doesn't know. On his website he also mentioned that there are no plans for a tour at the moment. Besides that Richard has probably his own projects going right now and might have declined a request by Mark to take part in the recording of a new MK album. Anyway, does it really matter? Mark is always able to surround himself with top musicians. For me it is mainly about his songwriting, vocals, guitarstyle and sound. With Mark that will always be the same.
Personally, i actually like a change in the line up from time to time. New blood means often new/fresh ideas and sound. Have a big dream (wish) though. A MK slide guitar album, with guests like Sonny Landreth, Jerry Douglas, Derek Trucks, Bela Fleck, Ry Cooder, Chris Rea, Jeff Beck, Paul Franklin (box)... even though that will never happen.. the dream is still beautiful. :-)
By the way guys and gals ever heard of Nelly Niel (aka Andrew Niel):