Kungen talks about the exact thing in his video:
https://www.youtube.com/watch?v=9MNFWhCw8dgI +1 for no Flying mounts, instead give ground mounts +speed if you have extra flying skill learned, yes, it sounds costum non-blizzlike crap, BUT remember, WorldPvP was destroyed when flying was introduced.
TBC will be fun anyways, but what more fun would it be with being in danger all the time, even as a max lvl raiding character, that still has to be on ground and can be ganked by other group.
I really doubt Nostalrius will go non-blizzlike route just to save WPvP, but yeah, that would be awesome.
- How about, Nostalrius releases flying when Sunwell is released? - Because everyone would be on the Isle where no flying would be allowed, so WPvP would happen there and lot's would still be in Outlands where they could finally fly

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No flying for some time would really give a FRESH new gameplay in Outlands. - Yes you can ignore flying mounts, but others in the sky will force you to fly, also people will randomly swoop by and gank you from sky instead of being able to see enemy in the distance running towards you..