Why? Have you seen Tucci? If they’re after an uncanny likeness, he’s got to be the go-to guy for the lead role. He’s also got the easy charm in spades, but he can bring the sterner stuff when necessary.
And he also has an affable, could-sell-ice-to-the-eskimos demeanour that would work well in third act scenes where he sells iPods/iMacs/iTunes/iPads to baying conference crowds. And he’s been a supporting scene-stealer for so long he deserves a title shot now.