It doesn't surprise me that WHDH wants to pre-empt Leno; Ed Ansen's notorious for knocking out certain shows for local programming. His WSVN in Miami lost their NBC affiliation because of this over 20 years ago.
Yeah...I remember that. It was a mess with affiliation swaps in S. Florida for a few years. NBC and Ed Asnin did not see eye to eye, and I think that NBC saw buying WTVJ as a way to stick it to WSVN. Things worked out well for him, though. WSVN became a stronger operation in the long-run, and has done will with Fox. They have some news operation in Miami. A real pioneer in the tabloid style format for TV news.
In Boston, when WBZ (along with the other Westinghouse stations) decided to flip to CBS, that left NBC scrambling to find a home in Boston. Fox and NBC really duked it out for an affiliation agreement with WHDH. Fox was on UHF and wanted to be on a VHF stick, and figured they could leverage their existing relationship with Asnin to make that happen...thus leaving NBC to move to a UHF stick. I was surprised when NBC won that one. You'd figure Asnin would want to stick it to NBC for what happened in Miami...but NBC won out in the end. I guess money talks. But I think he would have done better with Fox's sports lineup and American Idol, as opposed to the total crap on NBC.
Now with the DTV transition, there really is not much distinction between UHF and VHF anymore. In fact, low VHF (Channels 2-6) is all but being abandoned.