Ingame ads themselves arent bad so much it is just when they are intrusive that they are annoying. For instance if in a game there happens to be a billboard why not put an advert on it, but if it particularly draws attention to it by saying "Press 'X' to zoom in" inexplicably and instead of showing you a nice 'Vista' it pops an add in your face then yes that is bad. I actually remember being impressed at Burnout Paradise and how it incorperated ingame ads, I was less impressed with Cities XL 2011 Edition because it had billboards every 2' (ingame feets) from eachother.
EDIT: As 'thx1139' above me states, it also looks more like there will be the odd panel on the dashboard bringing attention to a film they just released on Zune or something, or allow you to check out your local cinemas and the like.
