I do think we are heading towards convergence, though. We're already seeing a proliferation of terms across the product ranges: you have a Nokia "Communicator" now and also a Windows "Mobile" Phone PDA.
The O2 Mini's managed to be "relatively small", compared with a standalone PDA, and this year we are expecting more models from Samsung, ETEN and HP.
Having said that, however, I do believe that current models need to improve on their usability. Not everyone enjoys or thinks it is necessary to go through the more complex PDA features; some would be rather happy to use them as sophisticated phones. So IMHO convergence shouldn't be looked at in terms of features, but in terms of the end-user's experience.
One thing for sure is that the lines between PDA and phones are blurring rapidly, and at this rate we'll have a Tricorder