According to this entry on the Microsoft Office Natural Language Team Blog, the new person in this job is Joshua Goodman. As folks who do natural language processing know, Joshua's got a strong track record in statistical NLP (ranging from n-gram language models to parsing) and he's been a leader in organizing anti-spam efforts in the research community.
I'll echo what Mari Broman Olsen writes on the blog: "Pretty cool to have someone who knows about natural language work in that role!" Way to go, Joshua.