I'm in this same situation too....I want to convert my useless card to something marginally better, even though I rarely ever use my B of A card. My problem is that I'm concerned about my account history going away cause this card was my first credit card after turning 18. I started off with the student visa and eventually converted it over to the only free product at the time (now the Platinum Plus Visa).

Now I wouldn't mind having something different, even though I don't use it much [all my spending goes on my Amex or my Chase Amazon). I called B of A and they said I was allowed to convert last time because I was leaving a student card to a regular card, but after I'm at a regular card I have to reapply for any other card I want.