Came across this article on WPCentral. Specifically look at the last paragraph.
Two things will determine if it is available--the chipset of the device and if the carrier wants it. The chipset in question is the Broadcom 4329 which is found in the newer Windows Phones. Specifically, drivers are need for it to work with that chipset. But ah! you say, what about that Samsung Focus we saw? A lot of our older hardware also has the Broadcom 4329 on board, but not the correct, tested drivers. ¿Por qué?
Microsoft had to make a choice: delay Mango to test the drivers on older devices, or ship now and release a patch later to enable. They obviously went with the former. But even Vodafone is aware of this when they said recently on their blog "Regarding Wireless Hotspot, it isn’t integrated in the initial release of Mango however it may be deployed at a later date." That's exactly the situation--it's basically up in the air at this point for certain phones.
I couldn't find anything specific that states the Trophy has the Broadcom 4329 chip on it.