[HEADING=1]THEY ARE NOT MILKING IT![/HEADING]
At least, no more than Infinity Ward or Activision are milking CoD, or Valve have milked Half-Life or whoever does the Lego games have milked the, um, Lego games...
There are three main games. Then one RTS, a spinoff (ODST), and now six games when Reach is released in September. I can think of plenty of IPs that have more games than this, and no-one ever complains about those (the entire series spanning around FF7 alone, for instance...). People only complain because Halo is popular.
Anyway, as a longterm fanboy I'm pretty damn pleased for this. I really want to see what happened to John and Cortana at the end of Halo 3. My theory is that the planet they're headed for is Onyx, what with it being pretty damn far outside the range of the rings (perfect place to stick a Shield World, after all), and they'll end up meeting with the rest of Red Team, Mendez, Halsey, and the surviving SPARTAN-IIIs. Given that some Sangheili heading towards Onyx weren't aware of the new truce between them and the humans, they could potentially be enemies again in such a scenario.
And if you understand that, then I applaud your great taste in gaming, as well as congratulate you for being one of the relatively few people around now who still care a lot about storytelling in games.