Right now, I have no confidence that material from Dragon/Dungeon will be added to the online Rules Compendium in a timely fashion. WotC couldn't even finish their 3.5 errata in time... how will they successfully integrate the full material from entire books as well as manage errata?
I have no confidence that the interface of the digital tools will be fast and user friendly. The DDI website is a complete mess.
I have very little confidence that the virtual tabletop, virtual miniatures, character visualizer, dungeon builder and so forth will ever leave a beta state... especially not in a month's time. I hope that I'm wrong about this.
I have no confidence that the material provided in Dragon and Dungeon will be as good or better than what Paizo did. What I've seen so far is OK, but the only people I've seen giving it "rave" reviews are shills or amateur game designers and writers who (wisely) don't want to jeopardize their chance of getting published via WotC.
If I'm wrong, WotC will probably get my money -- but only if there are no microtransactions expected for virtual miniatures or character portrait goatees or whatever.
But if WotC the DDI successful with a monthly fee equivalent to the WoW monthly fee, they need to really, really, REALLY "wow" us.
And so far, all we've seen are static screenshots and unfulfilled promises.