It's not up on the UMAtoday.com website yet, but I got an interesting email from them quoting RIM's CEO at a recent investor conference:
Speaking at RIM's 2008 Capital Markets Day on May 12, Jim Balsillie, co-CEO of Research in Motion (RIM), took the opportunity to acknowledge the tremendous progress UMA has made in the market. “Wi-Fi UMA is going remarkably well," he remarked. "It’s very compelling...This is happening, and it's happening fast."
"Some [carriers]saw it as a threat. I saw it as an enabler, an inevitability. In a sense, its hard to find a carrier that isn’t excited about it now." And he went on: "I think it’s just so compelling and so inevitable.”
The key word here is "carrier". RIM's entire business model is based on the concept of the carrier always being in control (albeit with RIM's network ops guys sitting behind them). RIM does not sell "vanilla" smartphone devices direct to end-users, like Nokia or HTC.
So although RIM puts WiFi into its devices, it only permits its use at the carrier's discretion. It's not possible for a company to buy 1000 unlocked BlackBerries from a distributor, configure the WiFi to work with their Cisco IP-PBX with an FMC client, and then source 1000 SIM cards from whoever they like.
Nokia takes the view that this approach is as valid as selling via the operators. RIM only plays one half of the market - and although obviously the carriers like this philosophy, it isn't the whole story.
This is why RIM likes UMA - it is perfect for devices which only feature "operator-controlled" WiFi. It is very far from perfect for those that sell devices that an allow direct WiFi control by the end user.