Most sources say the HTC Kaiser will be released in July/August, which isn't much longer than the release of the i760. It seems to be better than the i760 in many regards (with the little information we have, since both devices are not released yet).

i760 pros 60 x 110 x 20 millimetres; 150g
Looks sweet
Keypad layout in the front is awesome
Is slightly lighter than the HTC

HTC pros 58 x 110 x 18 millimetres; 160g
More ROM and RAM
HSUPA
3mp camera
Front camera for videoconferencing
Integrated SiRFStar III GPS
Is slightly thinner than the i760

Most sources state they have the same CPU (one source states the htc has a qualcomm processor), and both have windows mobile 6. In addition, the HTC should have more accessories available than the i760.