While I'm able to easily adapt for the lack of characters, I chose cleric since the last one that my group actually played was in second edition.
Admittedly one of my players played a cleric in 2e for what had to be 3 years of realtime campaigning, and is probably more interested in playing something 'different' now.
I've always had to pick up the slack and drop in an NPC cleric simply to balance out some undead-heavy storylines, but let the players know before the most recent campaign started that there would likely *not* be a priestly/healer type NPC tagging along with them, unless the story dictated so.
But I balance that out with more healing potions (and even more potent potions), as well as using the reserve hit point rules from Unearthed Arcana. After a near disaster and TPK of the group, I've also hashed out a plan with one player to use action points as a way to 'save oneself' if slamed too harshly. After years of running campaigns, I'm at the point where I don't really want character after character dying while new ones would have to find ways to 'drop into' the storyline.
But yes, more clerics, shamans, or mystics would be nice to see..
..Maybe a Psion too.