Microsoft's pattern has been pretty consistent though; they announce a few things early on, then announce more throughout the year.
The quality of those titles is clearly up for debate, and any estimates on the split between core and casual games at this point is pure conjecture. Note, I'm not defending this practice or saying I like it, but it has been pretty consistent.
I do question the need to bring up Sony and thier offerings in this thread at all though...don't we have enough threads already of "mine is bigger than yours" here?