Rumour has it that Intel is going to play safe with the integrated graphics on Nehalem. FUD Zilla claims the first Nehalem processor generation won't integrate graphics in the CPU die, instead Intel will use the multi-chip module (MCM) approach.
The site says Intel will integrate graphics into the processor in the next-generation Nehalem, I believe they're talking about the 32nm Westmere shrink which is expected in late 2009 or the first half of 2010.
MCM means you would end up having two or more of the same of different chips on the single integrated circle or, in our case, on a single CPU.
You will be able to achieve this by putting an IGP core next to the Nehalem cores and making the pin layout and socket for both chips. This is definitely a much safer approach than making the IGP physically on the IGP, but this will help Intel to make IGP Nehalem at some point in 2009.