What do I do with ~60 PR2-PR3 Web2.0s/blogs?

Mostly blogs scattered across the realms, about 50% tumbler and 50% mix of 15 other popular blog/2.0s.. Most of their content is grubby little articles, about 20% spun pointing to my tier1 sites but I have quite a few even a handful of some PR4 with 40+PA. I've been careful managing them and apart from toasting a pr4 paHIGH-40-something a month or two back from being a dingbat I've managed to keep them all safe. Should I be pumping out backlinks to my tier1s (mostly what I've been doing expecting them to eventually get nailed/dropped) or is there any hope in keeping their rank? Try and turn them into tier1s themselves instead of greedily making tier1s? or even into money sites etc? I do SEO history lookups and most of them had mad, sometimes 100,000s of backlinks and what not and I'm not doing any crazy gsa/blogposts/etc but I guess I should? They are a shell of whatever got them their rank with minimal backlinks if any and high OBL.

I just feel like I'm floundering and when the day comes that they start getting dropped I'll wish I did more. Thoughts/ideas/suggestions? Be candid be brief be detailed whatever ya got Any feedback is much appreciated.