I'm really excited on a very detached level of "What is 'lethal' for a system/design ethos that says 'reward players don't punish them,' 'bonuses not penalties,' and 'say yes, and...'?"I bet you the 4e version is no where near as pointlessly lethal as the original.
That said, I'm interested in running this for veterans of previous editions who have become accustomed to the 'friendliness' of 4e. The thing is, I suspect that it's either going to be a) 'It's nothing like the original Tomb of Horrors! What weaksauce!' or b) 'OMG, why did you run this?'
In which case, I'm probably going to look for players who are open enough to have some cheap laughs over a module that could go ANY way.