I can't believe people are willing to throw away Rahim Moore and draft another 2nd round Safety (like Phillip Thomas, who is older than Rahim) for one bad play. How many Safeties have the Broncos gone through in the last 5 years? How many Defensive Coordinators? Is it realistic that Fox and Elway would do that? Doubtful.
If you're talking about upgrading Mike Adams, that's fine...although he had a good year, and played well. The problem is guarding TE's. Elam won't be there at the Broncos pick in the 2nd round, and I wouldn't expect Cyprien to come in and play better than Mike Adams.
There are NO Safeties that will be available at #28, that are even close to the 28th best player in the draft, so drafting a Safety at #28 would be a major reach. #1 CB's are FAR more valuable than reaching on a Safety in the 1st round. If there is one available (not sure if Johnthan Banks or Jordan Poyer are that guy), you would pick the #1 CB without question.