If there's been on criticism of Halo over the years, it's the relative sameness of the experience.
Earlier today during a discuss of the new enemy designs in Halo 4, Scott Warner of 343 industries mentioned that some of their main inspirations for the development of the Promethean units were highly advanced, amorphous foes.
That design philosophy is clearly evident in the final product. Prometheans and their weapons can disassemble themselves and then reconstruct, and their broad abilities hint at technology far beyond even those of the Covenant.
At the same time 343 aimed to keep the same core battle strategies of Halo: "We wanted a strategic visual shorthand. Something that allows players to instantly understand the threat and how to react."
Commitment to redesigning the experience while keeping it in line with classic elements of the franchise was difficult, especially as their team swelled from zero to 340 over the course of development. Hopefully as this new team goes on, we'll continue to see a new vision for the Redeemer trilogy.