In Season 1 they were a lot more willing to decimate their cast, because they didn't plan on keeping any of them around for the second. Everyone you mentioned got fridged either in Season 1 or very early on in Season 2. I don't think there's been a really jarring character death since then - Bob Bishop's was predictable, and Niki's was cheapened by the fact that Ali Larter is still playing her heretofore unmentioned sister. So it's about time they had a really meaningful death - Elle probably fits the bill quite nicely.

If Mr. Muggles' first name is "Mister" I'll bet the Haitian's first name is... "The."