Now, I should caveat my judgement in that I don't know the assumptions, definitions etc in the full report & model, but even so, this is so far beyond the "smell test" I don't know where to begin.
But lets start with:
- Enterprise - UMA initiatives are going nowhere
- Prepay (seen any FMC models suitable for 70% of the world's subscribers? I haven't)
- Inapplicability to CDMA/WiFi (ie about 20% of users)
- Limited base of broadband homes with WiFi
- Refarming 900MHz to give better indoor coverage
- Falling cellular prices making homezone pricing irrelevant
- SIP & VCC standardisation coming with 3GPP R6 and R7
- Lack of WiFi penetration into handsets
Some of this doesn't apply if the stats also include non-dual mode devices using UMA (eg femtos), but it still looks out by getting on for an order of magnitude. I haven't redone my full model & forecasts for a while, but if I had to take a punt, I'd be being generous if I said 10 million subs by 2012.
As always, let me know if you'd like a disruptive second opinion.