I had to ask my Dell rep about this as I'm looking at Android development. I strongly believe that it will not take too long for that platform to be the most widely used, and have a very wide choice of phones all supporting the platform.
It's interesting to hear that the rumours are within Dell as well as outside and although its not official, it's certainly not being denied by anyone both externally and internally.. I suppose we'll all have to wait and see.
The first Android phones are meant to have an appearance at the beginning of 2009 from people like HTC (who I believe are making the most promising phones at the moment)
In the meantime, iPhone has released its 3G version, fixing the most widely requested missing attribute, though I still just don't feel confortable when using it. It also hasn't got the some of the capabilities that Windows mobiles have such as internet connection sharing etc. There are many eyes still waiting to see what Microsoft have behind closed doors with regards to Windows Mobile 7.0. The problem is that this might end up being too late unless they can really pull something remarkable out of the bag.