Today was an interesting day, as I got to speak to a few interesting folks at Dish and they passed along some interesting information to me, which I in turn am passing to you. 
The official release date of the External USB storage is August 15th, here there is a chance we could see it a week earlier.
Dish Network will officially support external USB drives up to 750 gigabytes in size, however other larger drives may work on the 622 / 722 but Dish Network will not be officially supporting larger drives at this time. (So in other words try it at your own risk, as it may work, or it may not.)
The official USB Hard Drive enabling fee is $39.99. (This confirms what was mentioned earlier today by MrBoylan.) this is a one time fee.
You WILL be able to move the hard drives to other 622 / 722's in your house and enjoy recorded shows on any of your 622's or 722's that you have. However you wont be able to bring your drive to a friends house and watch recorded shows on their 622/722. (This will work at LAUNCH, for awhile there they said they hoped to have this feature available shortly after launch)
An interesting feature was told to me, was that you will be able to somehow hook up your 622 to your 722 and transfer shows between them. (It was not explained to me how this was done)
And finally DishONLINE might not make it out in August, there is a glitch which they have found which may hold up its august release.
My thanks to the folks that I talked to today who passed this info along.

The official release date of the External USB storage is August 15th, here there is a chance we could see it a week earlier.
Dish Network will officially support external USB drives up to 750 gigabytes in size, however other larger drives may work on the 622 / 722 but Dish Network will not be officially supporting larger drives at this time. (So in other words try it at your own risk, as it may work, or it may not.)

The official USB Hard Drive enabling fee is $39.99. (This confirms what was mentioned earlier today by MrBoylan.) this is a one time fee.
You WILL be able to move the hard drives to other 622 / 722's in your house and enjoy recorded shows on any of your 622's or 722's that you have. However you wont be able to bring your drive to a friends house and watch recorded shows on their 622/722. (This will work at LAUNCH, for awhile there they said they hoped to have this feature available shortly after launch)
An interesting feature was told to me, was that you will be able to somehow hook up your 622 to your 722 and transfer shows between them. (It was not explained to me how this was done)
And finally DishONLINE might not make it out in August, there is a glitch which they have found which may hold up its august release.
My thanks to the folks that I talked to today who passed this info along.
