The Virginian-Pravda brought us an article on the planned anti-tax rallies on April 15, including the one planned for Virginia Beach's Town Center Plaza. http://hamptonroads.com/2009/04/hundreds-expected-tea-party-rallies-nc-va
So they hold their rally on the 15th, probably get media stories on the 16th...but what happens on the 17th? The article doesn't mention any long-range plan; it simply states they want frustrated people to know that they're not alone.
In addition, how much do you want to bet that the Virginia Beach rally isn't dominated by the usual suspects?
Finally, now having set the benchmark at 500 for attendance in Virginia Beach, anything less is a failure.
Cute idea that wasn't thought through.