Static .HTML, .GIF, .JPG and .JS files. That's all.
In principle, this variable IPs should be already known by G as it is known that those IPs belongs to Akamai.
The possible consequences could be thought in different directions:
POSTIVE: compared to the current situation, when Google know exactly that I'm serving 20 (different) web sites from a single IP address, the multi-IP condition will "confuse" Google and surely will think that all those 20 sites (that sometimes link themselves reciprocally as they are addressing different aspect of the same topic) are on different nets.
NEGATIVE: as the IP will be constantly changing while spidering our sites, Google will think that we are "dancing" too much and therefore we are, may be, not so reliable (Google bot could think "hei, every time I'm checkign those pages at #*$!x.com I find the site hosted on a different IP: these guys don't have a clear idea on where to host the site: may be the site is ging to be eventually dead, so I'll evaluate it with a lower ranking).
POSITIVE: as we are serving our sites located "close to everyone" and geo-distributed, we'll end up in being listed on the regional verison of Google, (we are not on every language version, today...)
What's your ideas on this?