While I am definitely looking forward to what 2.x has to offer, I am not losing any sleep over it.
Maybe it's because I am in the "It's just a phone" camp (a really cool phone with a lot of neat toys), I really haven't noticed any lag.
The apps open as fast as I would expect them to on a tiny little device. It actually loads quicker than my HP Mini.
The keyboard reacts quicker than I can type on it.
The GPS can take a little bit to sych up, but it's Winter in Minnesota. I ain't outside much right now.
The fetures listed in the article seemed like stuff that Sense UI already takes care of.
The onlhy real problem I have so far, and I'm not sure it's even an OS issue, is the time it takes for the phone to tell me I have a call. I have sat side by side with friends/family, had them call me, and listened to it ring 2 or 3 times minimum before my phone rings. THAT lag does bother me a bit, because it is a phone. It's nice that I can check facebook, run away from Zombies, rearrage gemstones, etc... But, if my phone doesn;t want to tell me I'm getting a call, I might just as well stuck with my Razr/Ipod combo.
In all reality, though, even that lag isn't enough to turn me off on the phone. I'm more than enough of a geek to enjoy playing with all the apps. And, if whoever is calling me can't wait 2 or 3 extra rings to talk to me, I didn't want to talk to them either...