1) Shields doesn't really want to stay at MW
2) Shields doesn't want Aoki because he thinks it'll be aneasy win. He wants him for the challenge on the ground. Can you think of anyone other than Marcelo Garcia (also much lighter) that has subbed Shields in anything
3) In the live interview, he also says that Strikeforce was the one that threw Aoki's name out there, not the other way around.
Shields would fight Trigg anytime any where, that shit goes back several years.
After Lawler, he's only got 1 more fight left on his deal (same as Lawler). It's unlikely Strikeforce will put him (or Lawler) in a title position unless he's resigned. So having each fight a 'Mega-Fight' in both fights is likely the best thing to do.
I highly doubt that Shields / Aoki ever happens though.