Just heard it on the radio as well.
This is a very good move for the following simple reasons:
A. We need a solid veteran backup who can jump in at a moment's notice.
B. Frerotte is ideal b/c he will immediately know the offense.
C. Feeley will take some time to learn the offense. Remember last year? He was very slow about picking things up. There is no certainty that Feeley will be able to immediately pick it up - Frerotte may, in fact, beat him out.
D. A rookie or Rosenfels would be unlikely to be competition for Feeley.