the DA-50 is what in the software business is called "vapourware",
The prototype looked pretty solid at San Jose today. It's a gorgeous aircraft, the rightful successor to the TR182 and the 210 (and the P210, given that it will now apparently be pressurised). But it's also true that you can't have one yet - the salesman was talking about 2010.
As for the stability of Diamond... have you seen what's going on with Mooney? Sadly, the only companies you can count on right now are Cessna and Cirrus. Everything else is a gamble - it even looks as though Eclipse will go under.
Also at San Jose was the DA42-L360, with two IO360s. I didn't get a chance to sit in it but I guess they must have made the console a bit wider to accomodate six levrs instead of two. They were saying it will ship in Q1/09, with the DA42-NG (with the Austro engine) later in the year. That would be the plane I would buy if I was in the market for one (which unfortunately isn't very likely at the moment, although my TR182 is more than fine for anything I plan to do anyway).
You really can't blame Diamond for the problems at Thielert. Curiously, there was also a stand at the Expo showing the Thielert engines, under another name (I forget what) with "manufactured by Thielert" underneath.
n5296s (or maybe oe-v50)