Actually, I kinda liked MI4 (OMG I'm gonna get killed now!!), apart from the fact that you couldn't use the mouse. Grim Fandango is good too.
As long as Lucasarts use their whacky humour I don't care if it's 2D or 3D - it's still good.
BUT Indiana Jones and the infernal machine is a different matter! YUCK! Fucking Tomb Raider clone I'd say.