1) Fair enough, I personally don't think £100 is a lot when you essentially get an 8gig iPod- but taken on board
2) Again, agreed with
3) You can recieve MMS, you can't send. Although if you jailbreak (2 minutes to do) you can send as well.
4) Again, with jailbreaking there are a tonne of video apps now
5) Personally I think it's fine for a "quick shot". Even the phones with great lenses really don't take great pictures. But again, this is important for some people
6) Apparently there is an app for this now, i'm not sure. But generally this isn't an issue? I use mine for work (sync'd with exchange) and I haven't come across a time where I've needed it
7) Jailbreak and you can use "backgrounder"
8) Who knows!
9) There are a STUPID amount of apps on itunes and even more if you jailbreak, and they are- on the whole a lot better written than say Windows Mobile apps
As you can see if you jailbreak (again, 2 minutes) you can overcome nearly all of the negative points of the iPhone. Even WITHOUT jailbreaking the issues aren't exactly big.
No MMS? I'll just email with an excellent email client?
Can't bluetooth a picture? Oh wait, it's not 1999
Etc...
I've been using windows mobile for a few years, and I loved it. It has "it all", but what it doesn't have is a nice gui and a good user experience.
Using a windows mobile to me is like going back a few years, everything takes that little bit longer and is just that bit more fiddly. (I support Omnia / HTC HD / HTC Touch Pro at work too).