Nokia have the N8 coming soon – looks promising and you get free maps/navigation on the phone
Personally, I'd avoid it – still has the Symbian operating system, which means far fewer and much worse quality applications for it, not as good a screen as the Desire (probably also not as good as the iPhone, but not sure). Hardly anyone will bother programming for it now, as Android and iPhone are a million times easier to write apps for, so you'll just be stuck using whatever nokia puts in free, and the things on Ovi store, which is pretty limited at the moment compared with itunes or android market.
Maps and navigation is a bit old now, it is a slight bonus that you can preload them, but the Symbian maps are not as good as the maps on Android (which also has free navigation too).
It'll also probably be very expensive (the rrp for the N97 is almost 2x the cost of the HTC desire), which might make a difference to how good a deal you get on it on contract.
Joe