Bank consolidations have always been common, but with this environment in which many banks are having financial troubles, it's even more common. This Money-Rates article
has a list of some useful steps to take when your bank is merged into another bank.
One thing not mentioned is that there's a difference between a voluntary merger and a takeover after a bank fails. If your bank fails and is taken over by another bank, more changes can occur such as rate cuts on your existing CDs.