An e-mail comment from Jimmy Wales, quoted just now in a Digital Spy article[1]:
"I'm happy to inform you that our current fundraiser is the most successful in our entire history."
The bottom line is that the present banners are evidently more effective at monetising the brand than those used in previous years, and an extra 10, 20 or 30 million dollars in revenue speaks a lot louder than the qualms voiced by a few easily expendable volunteers here.
[1] http://www.digitalspy.co.uk/gaming/news/a617618/wikipedias-jimmy-wales-repli...