I'm an Arrive owner, and I really love my device! It is rock solid, works well, and smooth with Mango.
However....
I've been through the Touch Pro, the Touch Pro2, and now the Arrive. A trend? I've always felt partial with physical keyboards. Hmmm.... lately, not anymore. I think I'd be content with a no-physical keyboard device any day now... provided the screen is a bit bigger than what the Arrive gives you.
Therefore, I am waiting for the next Sprint Windows Phone too! A dream come true would be a 4" or greater, SLCD, Gorilla Glass, front-facing camera, 8MP or greater back camera, uhhh.... etc. etc... big specs etc.... perhaps Samsung?... anyway, yeah, I'd like to see Sprint get one, or two... heck no, make it three! new Windows Phones in their aresenal. Think it will happen, anybody?