It would appear that 343 Industries plans to take the Halo series back to its roots with Halo 4 according to Microsoft.

Xbox Entertainment Director, Stephen McGill said to MCV;

“One of the key things with Halo 4 is going back to what made it amazing for people playing the first Halo,”

“The people who are 18 years old now were only eight when Halo appeared.
They probably didn’t play it. That’s the opportunity the Anniversary
pack and then Halo 4 have,”

“The tenth anniversary is huge and is a product of great passion. It’s
important we celebrate this – the game itself was a huge milestone for
us and kickstarted the platform in a lot of ways.”

“But the platform has evolved dramatically in that time, so it’s worth
going back to show how it still stands up as a product made today.”

Source: MCV