That sounds like a change in terms. I would call Capital One to clarify what is changing before you get more upset. Also Capital One credit cards hasn't gotten any government money like other banks have. Capital One doesn't do mortgage loans like other banks so, there is no financial strain on them like a regular bank. Change in terms like the one your got are not credit risk associated, so no fear there of that being the reason for the increase. Also as bad as this sounds, your good payment history would not prevent a change in terms.
The right to change your terms is in your orginial terms as that annual fee most likely was. As far as the annual fee goes, sometimes it can be waived, but considering the economy and the fact that the fee pays for the mantainence of your account, it's unlikely you will have the fee waived this year. If you have ever had it waived before, you are fortunate and should look at the years you have had the account, take the fee amount and divide it by the times you have had the fee waived...then the overall cost of your card is very minimal.
If you have not opted out of the change in terms yet, I suggest calling Captial One to get clarification on the change before you opt out.