I don't run an ad supported site either, but I buy space on them. Google will tell you how much you paid for ads on a per-site basis, and I just ran reports for the last 30 days and the same days for 2008.

Here's what happened to the three sites who made most from me last year. All three are names you'd recognize. [Edit for clarity: these are the CPMs paid Google. The sites probably get substantially less than 60% of these.]

Site A: Effective CPM has declined from $3.20 to $.80, spend declined 66%

Site B: Effective CPM has declined from $3.80 to $1.90, spend modestly increased (impressions obviously quite up)

Site C: Effective CPM has declined from $8.84 to $3.50, spend flat (impressions obviously quite up)

The kicker: I'm one of the few advertisers practically begging for traffic -- there are a few hundred bucks of slack in my budget, so if they've got it for sale I should be buying it. Its just the cratering CPM prices that are keeping my spend that low. My guess is this means that the other advertisers are sharply reducing spending, which means I win the "auction" easier and get the clicks for cheaper (thus decreasing effective CPMs).

No not in the least. Online advertising is still very strong from where I'm sitting.