I am in THE SAME boat as you. I have the same concerns and I also have a Palm Pre that is struggling and doesn't seem to want to even load text messages sometimes. I always thought the Pre had the best multitasking though and I anticipate I will miss that the most although this video below starting at 3:00 shows webOS-like multitasking.
YouTube - Windows Phone 7 multitasking demo
Also, I'm always on the internet and i'm worried that IE won't cut it in terms of experience before IE9 comes to the phone "later this year" which I'm also worried about since NoDo is also taking forever for people.
I'm also not sure if i'm in love with the device. I was hoping for a large screen and more features like hotspot and maybe faster processor but i've never had those so I can't say i'm in dire need of them, but they'd be nice to have. I really don't want awesome hardware to come out in a 2-3 months. I know it's the tech world and I can't say "5+ months from now" because theres always stuff coming out but I do want to use my upgrade and it doesn't seem like Sprint or anyone else is announcing anything soon.
Anyone help me out? I'm up for upgrade on April 1!