Google is Struggling with Backlinks

How important are backlinks to google - more about pagerank

[caveman]

Google is struggling with the role that backlinks play in their algo, perhaps more now than ever.

Witness:

1) Some older sites with various, umm, semi-spamish tendencies, have since Bourbon reappeared for the first time in a long while.

2) Some newer sites with not much else going for them other than tons of new recip IBL's, are rocketing to the top of the SERP's (not talking blogspam here; those are one way ;-) ).

This can only mean that backlinks, in some fundamental way, are playing a substantially different role now than in the past. What's the deal?

How can an old, SEO'd site with few backlinks get so many good ranking spots since Bourbon?
--Age of existing (limited) links more important that ever? (e.g., few but seasoned links matter a lot?)
--On page and site wide SEO more important again?
--LSI or related semantic requirements heavily weighted? (e.g., must meet minimal requirements WRT semantic variability?)

How can a new, conservatively SEO'd site, with tons of recips - but few one way links from authority sites - do so well right now?
--Theming more critical than ever (even if from recips)?
--On page text surrounding IBL's continuing to grow in importance? (stuntdubl, where are you?)
--Recips not being discounted so much?

How can this connundrum exist? Heavy recips working well; yet some older sites with very minimal backlinks but good SEO and theming are ranking well?

I'd say a little 3D thinking is required here. ;-) What do you think?