I have one word. Apple. It would make sense given their partnership with Itunes and it would enable heavy hitters to be able to run the computer show. Knowing U2, they will probably minimize the Apple logo, but will give Apple the bragging rights that they supported such a great tour.
I never understood the Corporate Sponsorship canard anyway. U2 has always maintained their creative control. The sick part comes in if Bono holds up a G4 and hawks it in a commercial (Britney Spears anyone?). It's not like U2 haven't worked with companies before, but they are very savvy about the working relationship.
Nothing to worry about folks. U2 have always used everyone else to their advantage, not the other way around.