I think McCarthy will keep his place. He is playing well. No need to change things. He is our long term No1.
After a shaky start McCarthy is really showing his quality now. As much as we all love Speroni I don't think any Palace fan can justifiably argue that he should come walk back into the team. We're second in the league. Unless he suffers an injury or a loss of form I imagine McCarthy will be our number one for the remainder of the season (and for years beyond). Tom Heaton being ahead of him in the England squad surprised me. I think it's only a matter of time before he breaks back in and potentially becomes England's number 2 'keeper.
Hennessey will probably push for a move in January. He's good enough to play every week for a lower half Premier League side. I'd love it if we could keep him though. Speroni may only have another season in him so we'll need two decent 'keepers. McCarthy and Hennessey battling it out would be good enough for me.