1. 0.99$ TV show rentals.
2. Ability to play H.264 720p video at 30 FPS which I believe the ATv1 was 25 FPS. Most video camcorders are 30 FPS out of the box.
3. Airplay
4. The 160 GB HDD is USELESS. Too small to have a decent library and needs to be synced with iTunes. Atv1 is not a backup device.
5. Better and newer hardware playing without stuttering
6. Netflix (even though you don't want it today). 7.99$/month for all you can eat video is more than interesting
7. Steve Jobs said that Apple Tv app store will come when the time is right so...read between the lines. There won't be any app store for Atv 1
8. 99$ (I sold my Atv 1 and got Atv 2 for the same price when Atv2 was launched. Maybe today, you won't break even but close)
9. Atv 2 runs cool and is small and tiny.
10. Atv 2 is more responsive.
I'm in the same position as the OP. The responses provided by benoitgphoto are more applicable if you are considering BUYING either an ATV1 or ATV 2 but since you already have the 1st gen, here's my $0.02 concerning his replies...
1. $0.99 rentals are available via iTunes on your computer--buy and stream
2. This is true--if you have a ton of 30 fps video, may be worth the upgrade. Nearly all commercially produced TV/Movie media is 24 fps and thus playable on the ATV1.
3. Also true--if you feel you need AirPlay, get the 2nd gen.
4. Moot point since you already own the ATV1. And FWIW, I bought a backup ATV1 specifically because it has a HDD. I have a ATV1 upstairs in our kid's playroom. Wifi signal is a bit weak so I sync all of their movies since streaming is not entirely reliable. We also bring it with us to our summer rental--plug and play that you can't do with ATV2. I've got 71 movies on it, almost half of which are 720p HD, taking up 118 GB so it's far from useless.
5. Again, this is dependent upon how you encode your movies. If you encode below the limits of the ATV1, no studdering. I have a ton of 720p HD content with bitrates over 6K and they playback via streaming just fine.
6. You said you don't have a need for it so, not a reason to get one. Buying the ATV2 IN CASE you change your mind in the future--not a reason to get gen 2 ATV.
7. See reason 6--there isn't one now so, also a non-issue. When the time comes and there is an App Store, you may find the offerings available worthwhile.
8. Irrelevant--you will spend $0 to keep your ATV1.
9. Also true but unless the heat from the ATV1 is an issue, it's a not issue. Also, it's not like the ATV1 is a huge behemoth---pretty much smaller than everything except the ATV2.
10. Probably true--no first hand experience. But the interface by all accounts is inferior as you now have your home media stored under the Computers heading and it's not nearly as slick and user friendly as the organization in the ATV1 UI.
Hey, I'm always looking for a reason to get a new toy/gadget and also tried to reconcile getting an ATV2 (we have 2 ATV1 still going strong) and sadly, unless you live off Netflix streaming, must have AirPlay and have a ton of 720p 30 fps home video, really is no reason to replace your ATV1.