No, they are not the final releases of phones from i-Mate, the Ultimate is just well a series which the company has decided to come out with at the same time. Saves us the hassle of creating seperate entries and reminding you of the earlier ones so its just as well. The 5 handsets belonging to this series all run on Windows Mobile 6.

From here on I will quote Gizmodo, since they make it sweet & simple -

All of them have a 520MHz processor, Tri-band UMTS/HSDPA, Quad-Band GSM/EDGE, 802.11b/g/e/i Wi-Fi, Blueooth 2.0, miniUSB, Direct Video Out, microSD, 2.0-megapixel camera, and FM Stereo, but here are the differences

• Ultimate 5150: 2.8-inch VGA touchscreen slider

• Ultimate 6150: 2.8-inch VGA touchscreen candybar

• Ultimate 7150: 3.8-inch Primary Touchscreen, 2.2-inch OLED secondary display, QWERTY flip-keyboard

• Ultimate 8150: 2.6-inch Primary Touchscreen, candybar shape

• Ultimate 9150: 2.6-inch Touchscreen, clamshell