look if Intel owned IMGtech they would have the advantage of superior manufacturing process: Intel is at least 6+ months ahead what ATI and nVIDIA can get (UMC, TMSC)... basically Intel could start with a one generation process advantage every 2 product cycles or so...
While ATI and nVIDIA both have 130 nm for the highest end CPU, Intel already has a large scale CPU at 90 nm...
IMGtech never had the manufacturing process advantage over nVIDIA and ATI... that would give them an advantage in clock-rate and transistors count...
Intel COULD start a high-performance GPU business ( They stretch themselves already that is true, but recently they got the whole EV8 team from Compaq and TWO design teams from HP )... first two iteration might be so-so, especially the very first one... but the third product would probably end up to be a bombshell under ATI and nVIDIA's feet...
If they bought IMGtech they could declare game over with the second GPU produced IMHO...