Thanks for the advice on the catchers, Mikeblid and Nick. Both are definitely the best defensively in my organization. I'm going to keep both, check the free agents for alternatives, give them both a shot in spring training, and then maybe waive one of them. Who knows, since their strengths are durability (73/90), health (88/91), and handling pitchers (87/96), they could be trade bait as soon as the injury bug begins to bite around the league.
Coco - If you're absolutely sure you have no use for an arbitration-eligible player, you can release him before arb with no adverse budgetary consequences.
Based on the above advice regarding my catchers, however, I've decided to keep a few arb players whom I was going to let go. Example: 3 fringe pitchers asking 700-800k. By the end of Spring, I'll probably try to get two of them to AAA (injury insurance) via waivers, but the worst that can happen is that somebody else takes them (and their salaries) off my hands.