New maps seem pretty interesting. The changes to the COD4 maps surprise me - I'm sure the geometry and design is basically the same, but the actual texturing and lighting has been changed quite noticeably. Vacant doesn't have that blue-ish look anymore and I could barely recognise Strike for a second. I had no problem with Overgrown and Crash looking the same (though Overgrown does consequently look a tad ugly in comparison to the MW2 maps) but I'm liking these changes.
As far as the new maps go, I'm actually looking most forward to Fuel. If it's supposed to be a sniping map, that doesn't bother me since I actually think Snipers are given a bit of a tough run in the game - essentially only Wasteland, and maybe Estate are sniping maps. Otherwise sniping is a bit pointless, so it's good to see another map that encourages it.
Carnival should be pretty interesting - lots of new assets should make it really fresh. You see the Trailer Park assets all the time in the single-player and spec-ops (and even in multiplayer with Scrapyard) so I'm not overly keen on that one, but then again the addition of Salvage meant yet another snow map and it still turned out to easily be the best of the new three.
Hopefully all three are more along the lines of Salvage, and less like Storm and Bailout, which aren't particularly bad (actually Storm gives me nice Downpour/Pipeline vibes) but weren't much better, if at all, than the original maps.
Are we likely to get a third map pack? Wouldn't mind seeing District and Backlot (or even Crossfire) get a run in the game. Also think the game could use a map with some significant lighting changes - perhaps a darkened level like the EMP scene in the campaign?
Only problem is that MW2 doesn't give you night-vision anymore, though you do get the choice of thermal.
Actually, I think there a variety of locales in the single-player that would still provide great choices for maps - such the suburban washington (which is kinda covered in Bailout but not particularly well) or the oil rig. Hopefully there will be a 3rd map pack then before Black-Ops' release.