The Samsung Galaxy Tab Wi-Fi Tablet may have other components that differentiate it from the Galaxy P1000 Tab. Both devices are based on SoC that includes a Cortex A8 processor to 1GHz, but the other modules of the system would be different.
Not only lacks a module dedicated to cell connections, but the Galaxy Tab P1010 SoC also adopted a PowerVR SGX GPU 530, version immediately prior to the PowerVR SGX 540 fitted with the Galaxy Tab P1000.
The different hardware platform would mean in more modest multimedia performance, WiFi-only model compared to the Galaxy 3G Tab. Recall that the savings between the two versions is about € 50.