I found what looks to be Prototype footage of Contra 4 from 2007 E3. You can watch it in the embedded video link below. Contra 4 came out before the retro craze had really caught on. Back then 8-Bit City even operated under the assumption that there was not much 8-Bit new going on at any given time.
Mega Man 9 and Contra 4 were both big reboots that jumpstarted the recent retro revival on the last 5 years. Cave Story came out around the same time as well--the past was back. Geometry Wars perhaps deserves some credit too, because it was on every XBOX 360 in every store display you could image from 2005-2007. Games like Super Meat Boy, Braid, and Mega Man 9 would dominate the downloadable new frontier which had just been created.
While these downloadable titles may have been seen as second-rate (inferior) to the big-budget titles sold in a disc in the store, the lines continue to blur. Players are not as impressed with graphics as they once were, and a downloadable project is a better place to test out new ideas than a 50-million dollar blockbuster.