According to the rumormill, Google Wallet is not only coming, but it will end the problem of click fraud for Google. Supposedly, a click-through would only result in payment once the user purchases something from the advertised site, using Google Wallet of course. Exit CPC, Enter CPA.
That would probably be great news for Adwords advertisers, but potentially bad news for Adsense publishers. Adsense would then simply be another affiliate program. Affiliate programs work well for some sites, but the whole appeal of Adsense (for me, at least) was that it could work well where affiliate programs did not.
We'll have to wait and see how this pans out, if the rumor is true.