With the lackluster adoption of Vista, perhaps Microsoft plans to migrate XP users by attrition—one service pack at a time. The company today released Windows XP SP3, which enables in XP a slew of features, many native to Vista.

Available now as a stand-alone installer pack, the update brings XP users to Peer Name Resolution Protocol 2.1, the version of Microsoft’s peer-to-peer technology used by Vista to learn of and communicate with other Vista apps and Web-connected systems by name. It also will allow XP apps to do the same with those on Vista. PNRP 2.0 was introduced in Vista and was made available for XP in SP2 in Aug., 2004.

Service Pack 3 also delivers Network Access Protection, Microsoft’s system of controlling access to servers based on the health of those servers. The technology is built into Vista and Windows Server 2008 and involves NAP clients, NAP Enforcement Points and Server 2008-based Health Registration Authorities.

Redmond in the past has acquiesced to the reality of slow Vista uptake by extending XP’s time on earth. The most recent example came last week when Microsoft CEO Steve Ballmer said “we will listen” to requests to make XP available beyond June 30.

Also included is support for WiFi Protected Access 2, Digital Identity Management Service, Microsoft Management Console 3, MSXML6 and Background Intelligent Transfer Service (BITS) 2.5, needed by Microsoft System Center Configuration Manager 2007 (and “snap-in” development framework) and Windows Live OneCare security service.

The latest XP patches will be available through Windows Update on April 29 and according to an unconfirmed report on TechARP.com, will be pushed to XP systems on June 10.