Multiple sites switching IP's?

[Kolaoya]

At this comapny we have like 30 differente sites.

many of them on same IP

some of the lesser sites have a PR of 2

i was going to create micro sites and market the main products but since these centent sites have pr of 2, what if i switch them onto its own IP?

by switching it will this help or will google see this and stilllump it together as the IP of the main site

what is a good suggestion i do with thease content sites