I've only had a few minor slowdowns with Outlook.com, but I noticed a complete lack of spam this week. Formerly my Junk Email folder got a slow trickle, about 1 message per hour, and I could tell how recently I'd checked mail and emptied Junk, with the same few dozen topics showing up. This week, only one semi-junk message (an unsolicited ad, with what looks like a valid and relevant return address, rather than the typical random address at an unrelated hacked site).