It pissed me off when I read the line about the hardware being unable to tether. I don’t know what they gain from this either – other than most customers will take the statement at face value and trust them. Froyo would allow them to not only enable wireless (and wired) tether but to CHARGE for it. So, they wouldn’t be missing out on their MiFi money. Customers have shown that they are willing to pay an extra fee for tethering.
I’m still rocking the original T-Mobile G1 and am running a custom ROM (T-Mobile has left the G1 at version 1.6 aka Cupcake). I have installed a preview build of Froyo which worked well (once I turned on a mod to compress RAM). Via custom ROMs with all versions of Android I have been able to tether with a usb cable, via wifi or bluetooth with no problems whatsoever – and this is the oldest/slowest hardware that runs Android!