No one forced anyone to buy an 800, so it the 800+ pisses those owners off, then I suppose they don't have to buy the 800+. But product updates/enhancements and other models happen with any good company. The whole idea is to get better over time.
I saw the same thing happen on the guitar side when Mesa put out the Mark V:35. Some of the V:25 guys got a knot in their face over it because they felt that Mesa had somehow devalued their V:25 by bringing out the "superior" V:35.
Odd thing is, it's probably been a year and I still see people posting pics of their new V:25s with very few new V35s. Just because something is bigger and has more features doesn't mean it's going to sell as well.