To me, the question is beguiler or no beguiler... and that depends on your players and your play style. If you have a player who is good at coming up with creative solutions and you as a DM are comfortable with being flexible about them, then give that player a Beguiler. It will be a lot of fun. If either of those things aren't going to work out, then don't use a Beguiler.
Party with beguiler
Dragon Shaman (human or halfling) - healer, buffs, ranged (make sure it has a decent Cha)
Beguiler (human or gnome) - traps, utility spells, trickery, skills
Warlock (human) - blaster, UMD (take extra invocations for flexibility)
Knight (human or dwarf) - tank
(if you want more melee, you can sub a Duskblade for the Warlock. You could also sub a favored soul in for the Dragon Shaman)
Without a beguiler, you'll want a flexible caster, a skill-based PC, and a trapfinder. A spellthief could work - as long as there are ample things around for it to steal from (you'd probably want another caster in the group, at least). A scout could help, but you'd want to replace the Dragon Shaman with an Archivist or Favored Soul... or something like that.
-Stuart