Mojo Identify Device

To tell if you are running on a Pre or a Pixie or some other future WebOS device use this call:

Mojo.Environment.DeviceInfo

It should give you back an object something along the lines of this:

{ "modelName": "Pr?", 
"platformVersion": "1.0.2", 
"carrierName": "Sprint", 
"serialNumber": "Unknown", 
"screenWidth": 320, 
"screenHeight": 480, 
"minimumCardWidth": 320, 
"minimumCardHeight": 188, 
"maximumCardWidth": 320, 
"maximumCardHeight": 424, 
"keyboardAvailable": true, 
"keyboardSlider": true, 
"keyboardType": "QWERTY", 
"wifiAvailable": true, 
"bluetoothAvailable": true }

The documented values (as of 2009/12/10) are

{"screenWidth": INT (px), 
    "screenHeight": INT (px), 
    "minimumCardWidth": INT (px), 
    "minimumCardHeight": INT (px), 
    "maximumCardWidth": INT (px), 
    "maximumCardHeight": INT (px), 
    "keyboardType": STRING, 
    "touchableRows": INT} 

I would guess that the other fields probably won't go away or change in weird ways, but one can't be certain.