An AndroidSPIN source, who claims to be a Verizon employee, said the update is slated to begin August 6 and run through August 15. If true, this coordinated software update between HTC, Motorola, and Verizon would be the first of its kind. Typically, Android upgrades trickle out in a seemingly random order, often preceded by some form of announcement.
It's also interesting in light of the user interface differences on the handsets. The Droid Incredible runs HTC's Sense user interface, the Droid is powered by a stock Android experience, and new Droid X runs a slightly modified Android with a practically transparent MotoBlur interface.
Consdering that Android 2.2 was announced in May and released to OEMs and ODMs in June, it makes sense that at least one of these devices would see Froyo by now. Motorola and HTC both have promised 2.2 for their respective devices this year, but have not committed to a time frame.
On a related note, the Droid 2 could arrive in late August with Android 2.2 under the hood. Having four high-end devices on the market with the latest version of Android would definitely send a signal to the other carriers. Could all three players logistically pull off a sneak attack next week? We'll find out soon enough.