Can't believe I have only just seen this thread; congratulations man you won't be disappointed.
I was in the exact situation a few months ago and went for an M3 in similar spec as yours; I can honestly say, hand on heart, that this is the first car I would be happy to keep forever. Only disappointing thing is how quiet the exhaust is at low revs, but I'm hoping a 2 pipe mod will sort this when the weather gets better (even standard it sounds great over 4k rpm).
I can appreciate why some people in this thread would hate on the car, as it does look a bit boring compared to some of the choices here, but the engine is a masterpiece and is really well matched to the DCT box; if you want a car to enjoy driving you have made a great choice.
The only car I would be tempted to change it for at the moment is the R8, which would be even more money on top so I can't see it happening imminently. MPSS on the back gave a great deal more traction than the PS2s.
Have a good look at the manual as this was the first car I have ever found it useful to do so; loads of little tricks to learn particularly regarding the DCT. Finally, don't worry about the fuel consumption; I get about 20mpg on average when I was expecting about 14!
Congratulations