I'm not here to discuss the wording of the fundraising slogans yet again, but this one screams "legal trouble":
Wikipedia. Ad-free forever. [Progress bar] [Donate now button]
I'd interpret this as "if we reach $7.5M, Wikipedia will be ad-free forever". I really wish that'd be the case, but if not, people (from simple dudes to legal trolls) might come out of the woodwork screaming fraud.
Or maybe I'm just too paranoid.
Cheers, Magnus