You are right - a great blog mention (like TechCrunch) is the most valuable... the value of a blog link quickly diminishes though as there aren't too many massively trafficked blogs.
Also, I agree with Ryan regarding the type of audience one wants to reach. For me, TM is my first source for news in the morning because whatever is listed there is important, and therefore valuable.
Up and coming tech bloggers like Louis Gray or Corvida can gain targeted audiences because of TM.