I thought it was tastefully done. They even mentioned they were running a "light ads" site.
Why would they want to serve their pages to people using ad-blockers anyway?
What would you prefer they have done?
I'm not actually running an adblocker, I'm running RequestPolicy and NoScript. Forbes.com and forbesimg.com are allowed as are requests between them, but I'm not going to go through and individually allow requests out to multiple other sites just to see which one is serving ads (though I suspect it's the permanently-marked-untrusted doubleclick.net).
They want to lose visitors, fine.
What they're forgetting is that people who have ad blockers also share and post links to various networks... they aren't just shutting out the ad-blockers, they're shutting out anyone the ad-blockers may be friends with. It's retarded, but it's their prerogative.
Incidentally, here's a great host file blocker for programs that run ads but don't support ad-block plugins.