Hello. WDBJ does NOT allow waivers. I called twice and was told that they simply do not do waivers, they will lose money. WSET will not do a waiver either, althought they don't even broadcast in stereo.
The chances of CBS in HD is very slim!!!!
To get WB and UPN, you might get the D1000, if they have any in stock. I would call ACS in Roanoke, they do the Lynchburg installs, and ask them if they would install the D1000.
As far as advantages, not many, other than you can have WB and UPN and the VOOM HD channels, if you want them, without having a second dish.
ACS, for the 61.5 dish, installs a second D500 dih, 20", with the Y-adaptor and one dual LNB. You could see if they still will do the 61.5 dish for free, you could repoint it to 129 later, or, if more HD programming, like locals, are put on 61.5, you'll already have the dish for 61.5