Aping a popular franchise's mechanics and style may be seen as a safe business proposition, but in terms of critical evaluation, the copy-cat game is likely to face stricter judgment. After all, if you're going to copy the good stuff, you've got to get it right.
Tecmo's PlayStation 3 exclusive, Quantum Theory (just Quantum outside of Japan), certainly succeeds in evoking memories of Gears of War -- at least, if you remember Epic's shooter being a technically unsound and completely unappealing disaster.