(UPDATED 3/24) NEVER SEEN SCREENSHOTS!!
in this update: A2DP headphones, tethering, MMS, and bugs
Last week I had the pleasure of trying out the new iPhone 3.0 OS. First I will have to say that I really like all the new features. The copy and paste worked great for me. All the new landscape features were quite nice also. A lot of questions have been coming up though regarding the landscape SMS and MMS now being built into 3.0. I know many people will be satisfied with the stock app when 3.0 arrives, but I believe there will still be a large market for QuickSMS. The stock SMS app in 3.0 runs quite well for what its supposed to do, but it still does not give the functionality of QuickSMS. QuickSMS has revolutionized text messaging giving the consumer complete access to SMS anywhere in the OS.
If you have contemplated trying the 3.0 OS do beware. You must have your UDID registered with Apple to activate your iPhone running 3.0. Also, if you do get your iPhone registered and think you will have access to all the kewl new things of 3.0, take a deep breath and re-think it. While you do get all the Glories of landscape SMS, email, notes, stock, ect… MMS currently is not activated on one of the ends. I called AT&T and was not able to get anywhere. What was weird though is that I had SwirllyMMS working on mine and my girlfriends iPhones working great, but mms failed every time in 3.0. This tells me that either AT&T will be using a proprietary protocol for iPhone mms or that Apple just didnt finish the code for it yet. After finally getting 2.2.1 back on my iPhone swirlymms worked just fine.
Also, one thing I did notice about 3.0 that I have not seen mentioned anywhere is the gps locate me speed. I noticed a very significant speed increase in the amount of time it took for maps to locate me. From the time I opened maps to the the time it took to get an exact location with the glowing blue dot was under 5 seconds every time! I am really glad Apple has put some time into this since they have allowed the capablities for turn-by-turn now. I did think at first that it was just faster because of the new install being fresh, but even when I put 2.2.1 back on it slow and very innacurate. so, I dont know if anyone else has noticed this, but it sure made a big difference to me.
Lastly, is 3.0 all that? Personally no, the only reason I udated to 3.0 was for the landscape email, sms, and native mms. Since I was unable to jailbreak to get my swirlymms back on I decided to revert back to 2.2.1. The only problem was, it took me 8 hours to finally get 2.2.1 back on my iPhone 3g and working properly. So unless you just have to try it and cannot go on with your life without being dissapointed by it dont even bother. Right now I am very content with my 2.2.1
(UPDATE 3/24)
Updated back to 3.0 last night since now I know how to downgrade if needed. I did becuase of some new discoveries of enabling MMS and tethering by updating the carrier settings.
First, yes tethering does work along side of MMS in the carrier update I used. There were reports that the bluetooth tethering wasnt working and only USB did. Well, my USB tethering didnt work and bluetooth worked great. It was actually pretty simple. One question I had before doing this was if it would work on a iPhone 3g without 3g service (we only have edge where I live) and yes it does!
Next, I have seen several questions regarding bluetooth headphones. I went ahead and tested this with my FreePulse headphones last night. They paired fairly easily and connected very quickly with no problems at all. As you can see below there is a new option now in the YouTube player (i had no music on it yet) right next to the volume control to switch the audio to the bluetooth headset. I did have a problem though. Once i switched the audio to the headset, the headset just turned off as soon as I hit the play button. I guess their still working out the bugs there. So I wouldnt update if you were hoping to use your new bluetooth headset with 3.0.
Lastly, I have noticed several bugs but only one that I have a screenshot for. Below you will notice that when I tried to switch to landscape mode after importing pictures from my camera roll that the keyboard would not swich into landscape mode properly.
If anyone else has tried 3.0 and would like to post their results, please do 
Marek
I have the same keyboard issue as You do
Also I have sometimes phonebook crashes, when I enter the Recent call list.
Facebook app doen’t show any pictures, even thumbnails.
Sometimes sound just dissapears. After restart goes back normal.