My main irritations with iOS6 are:

DND - It's taken 6 versions to get to a "do not disturb" feature, nothing is more irritating than the spam waking you up in the middle of the night. I'd like even more granularity and options than what iOS6 offers, so maybe in another 6 revisions of iOS it might get there.

Maps - Shit, double shit and completely fucking shit.

Work email - i'd like this on my phone, but again more granularity (i.e show me/notify me of work emails during the working week) I'm pretty sure that Android can be made to do what I want.

Tethering - I dislike the fact that despite their "brand", they still bow to the networks and disable tethering.

Widgets - come on, this is *basic* stuff.

Accessories - Made for iPod. Pfft. If you search hard enough the actual apple documentation on the authentication chip & the protocol is on the web. Auth chips are easy enough to come by if you take something apart that has one in....

iOS6 is nothing more than iOS5.01, very little appears to have changed and new features are just well, pathetic.

I've been a massive fan of the iPhone & iOS from the 3G to 4S, but I just feel disappointed with what I've seen so far - and new hardware (iPhone 5) isn't going to fix this because the problem is the OS now.

Edit:

Oh and thanks guys, much appreciated insights and thoughts on the matter. Will be interested in your thoughts Mark after being out and about with it, I use my phone a lot while on my commute to the office (London<->Ely).