I highly doubt Dodd, Bennett, and Reid all keep their seats.
Chris Dodd-CT is vulnerable because of the scandals that occured during his recent term as US Senator- Mortgage Scandals- His role as Banking chairman during the financial meltdown, his decision to move to Iowa during his failed presidential run, has caused his popularity to be at a low point. Dodd-CT is an established figure in CT and he keeps his seat if economy recovers, and health care legislation passes- plus all the bad stuff that occured with Dodd becomes old news.
Harry Reid-NV always faced and won close races during his US Senate careers except for 2004 due to his seniority status and ability to deliver for the casino industry- In CT and NV- the incumbents- Dodd and Reid can deliver for their states than Simmons or Lowden- who will be backbench Republican house members.
Bennett-CO is more likely to lose because he does not have the seniority clout that Dodd and Reid has.