Gateway goes to planning at CCC tonight, then WDC next Wednesday. Both have given it outline approval, but there are 500+ objections. The airport "only" got to about 900, and that was at the inquiry stage, so I'd say that's pretty vehement local opposition - even above the usual 7-1 ratio you might expect. Supporters barely number about 20.
As for the airport, there's quite a lot of "suspicion" that the Gateway will be used as leverage to push for more commercial flights, or even that closing the Bubbenhall Lane will make it easier to built a runway extension.
I would simply ask how and for who? To support the kind of ops Thomsonfly put on, you need a catchment of 1m+, so a few office parks won't make any difference, especially as very few of the TOM routes were aimed at biz pax anyway.
Maybe a bit more GA + exec flights, freight might get some new clients, but I suspect the real appeal of the new units will be direct access to the A45/46 + M6.