Well, seeing that the Photon is the 2nd best phone out there, It comes down to "Is the Photon suitable enough to restrain from waiting on the E4GT?" There are some pros and cons...
Photon - TegraZone, Possibly better sowftware support, probably more durable, qHD (Even with Pentile it still looks good), Kickstand, Motorola phones usually have better reception and GPS than others,
Epic 4G Touch - Bigger screen, Super Amoled Plus, better camera, better processor, MHL, more video codecs (DivX, Xvid), better UI (IMO), fastest browser, thinner, lighter, sexier (we all know it).
If the Pros on the E4GT are worth waiting for than go for it, but if you really want a phone right now, I don't think you would be disappointed about the Photon.