I picked Leica because they're irrelevant, and Pentax because they have nothing eyecatching on offer.
I don't see how Canon, Nikon, and Sony could have problems. They're the most popular DSLR companies right now, and I don't see that changing now. Panasonic isn't going away with their new G1 being released.
Samsung is pretty much out of the DSLR market anyway, and have essentially conceded by saying they're going to focus on making a u4/3 competitor, where the market is still up for grabs.
Panasonic was also barely in the DSLR market, so who cares. Like Samsung, they're moving on. This is actually the smartest thing Panny and Samsung can do. Get into this new market early.
Between Canon and Nikon, I think Nikon is going to have the better year. I like their D90 and D700 better than the Canon 5D- MKII and 50D, but that's the only reason.
Interestingly enough, I got a chance to try the D90 and D700 around 2-3 days ago at a Bic Camera. Awesome.

Also tried the 50D, Sony A350, Pentax K20D, an Epson Digital Rangefinder, an Olympus E-420 paired up with the 25 mm pancake lens (VERY small combo......not bigger than the Panasonic G1 in an impractical way) and some pretty sweet lenses.
