John Funk said:
Beyond just weaponry, Reach will add new Covenant races like the Skirmisher, a fast and nimble enemy that OXM describes as looking similar to the birdlike Jackals. Of course, the game will likely offer no explanation why said Skirmishers are completely missing from any of the games in the series that take place chronologically after Reach (which, at last count, is all of them). The perils of making a prequel, I guess.
Actually, Bungie have been very good at providing in-universe explanations for discrepencies so far. For example, Sgt. Johnson apparantly died on the first ringworld at the end of the first game, yet still appeared kicking Covenant ass in the sequels. Bungie subsequently explained it by writing a book whereby several characters, including Johnson, escaped and then kicked more Covenant ass by destroyng a fleet that was about to attack Earth (which also explains the other discrepancy that the fleet attacking Earth at the start of Halo 2 was so unexpectedly small). Not to mention the video from Jenkins' helmet in the first game where Johnson is attacked by the Flood. A graphic novel shows him escape, and then he's stated in the backstory to be a Spartan-I, so has enhancements that stop him being affected by the Flood.
This has probably gone over most people's heads, of curse. However, the point I'm trying to make is simply that any plot discrepancies and holes will be sorted by Bungie. They have a very good track record at making sure that everything is completely canon
. As far as the game is concerned though, as a Halo fanboy I'll be playing it regardless of the scariness of the Covenant. All I ask is that Bungie and MGS continue to provide such an awesome series as they have done, and that the game is good. If they meet that request, then I'll be getting it. If I want scary, I'll go out and buy a copy of Clock Tower or Silent Hill...