Can almost guarantee that this'll be cross-platform, and doubt that that will ever mean PC leads the way. They'll always build according to the lowest common denominator - and that's console controls and menu systems.
However - Deus Ex traditionally isn't as much of a twitch type shooter like MW2 is. Games like this dont seem to suffer as badly as the twitch type, as they tend to be a good bit slower, and more thought out. Games like Fallout 3 are probably as close to identiacal across all platforms as any - and equally as playable.
Multi-platform titles still have one ace up their sleeves (so long as the developers allow it) and that's modding. One of the most important mods made to Fallout 3 (and one of the first!) was to improve the user interface to be more suitable for PC monitors and resolutions. Allow this to happen (or better yet - do it in-house!) and it can be perfectly fine.
Either way - we wont know until we get closer to some sort of release date. Until then - my hopes will remain sky high!