The Security Essentials is designed to be bottom of the antivirus rankings story broke 2 weeks ago.
In response, Microsoft states: Our commitment to Microsoft antimalware.
Source: Mark Russinovich via Twitter
We are fully committed to protecting our consumer and business customers from malware. Our strong solutions provide the comprehensive defense needed against malicious code and attacks. Our support of antimalware partners helps in building a strong and diverse ecosystem to fight malware…We believe in Microsoft antimalware products and strongly recommend them to our customers, to our friends, and to our families.