Obviously I have no idea about projected budgets for next season (assuming we don't go up or down, I don't think either are very likely) or any negotiations that have taken place. I wouldn't rule out the possibility of us signing Martinez permanently if the money is there to do it - he'll be nearly 24 by the start of next season, Cech is going to be Arsenal's keeper for at least another three seasons after this one, Ospina is still there for now, he isn't really Arsenal level anyway. Seems to me around the time they would look at selling him, I don't think there's much doubt that Ken rates him significantly above Ikeme (and I agree), if we were to sign him then that could be our keeping spot nailed down for a long while to come.
If we have absolutely 0% chance of signing him then I could see why we'd do it your way and send him back. We'd need to sign another keeper though as McCarey isn't up to this level, Flatt is untested at Football League level, the other kids are too young and Ikeme doesn't even deserve the shirt at the moment, plus his limit even when he's playing well is quite clearly as an average Championship keeper, no more, he won't develop any further now. Again would depend on budgets - would we fancy terminating a loan (at possible cost) and spending a chunk of budget in January on a keeper when we have that area covered for this season? And of course if I had my way none of this would be up to Kenny Jackett anyway as I think his time is up.
Ojo can do one as he's quite frankly useless whenever he's trusted with a start and his diving pisses me off.