I am always looking for some advice from a tech savvy, they are really hard to find (in my world). So sometime I tried to write to some knowledgeable people on the web. Here is a response from one of them:

GaAs is a well-understood material used in all LEDs and a lot of RF.

There is a lot of interest in optical interconnect, which I guess is POET's key technology, but I didn't read the presentation because it's so wordy. Intel has dedicated research to making lasers on silicon so that the GaAs that POET uses won't be required. It's easier if you can make everything on a single chip, and that chip is cheaper if it's silicon.

Keep in mind that Intel made its first PCM memory chip in 1969, and that PCM technology still hasn't taken off. Optical interconnect could take equally long to develop.

This was not a lot but I guess there are things to learn from it. Firstly, this could be one of the reasons why Intel will not be one of our partners (at the beginning at least), remember Dr. Taylor at the EmpireClub . Secondly, Poet seems to be in the perfect ballroom with optics and single chip. Thirdly, he is kind of lazy. Fourth and last, we know something he doesn't know.