The MSN Alerts service has now been migrated over to Windows Live, and is available from http://alerts.live.com.

"Get headlines from your home town, scores and updates for your teams, stock quotes, traffic for your commute-just about anything that is happening right now. You pick it, so it's the stuff you want to know about, and nothing else."

Windows Live Alerts provides notifications either via Messenger toasts, email, or direct to your mobile device. While Windows Live Alerts as a service is free to use, some of the content may not be. You can sign up at this link for Liveside alerts. (Thanks BV2312 for the tip)