At long last, Windows XP Service Pack 3, certain to be the final Service Pack for the beloved XP, is off to "manufacturing." Of course, since there's nothing to actually manufacture, that just means they're priming the system for delivery to you via Windows Update. And that begins on April 29.

ZDNet has a helpful blog post answering just about every question you could have about SP3. The big info: Download via Windows Update will be about 70MB, and enhancements will be minimal. Security is the main focus, with some of Vista's enhancements (yeah, I'm nervous about this too...) showing up in XP. Of course, all prior XP updates are included in this roll-up as well, so if you missed something along the way, you'll be getting it come next Tuesday.

Answering one big question you all have sent my way numerous times: No, performance is unlikely to be affected by SP3 in any significant way.

Another biggie: Internet Explorer 7 is not included in the Service Pack, but updates to both IE6 and IE7 are packaged into the rollup, so your browser will be updated no matter what you're using.

One neat feature: If you have an XP CD with SP3 already on it (and these can be made by "slipstreaming" the update into your existing XP disc), you can install Windows without a product key, just like you can with Vista, and provide the key later when it's time to validate.

On the whole, don't expect an awful lot from SP3. While service packs normally bring with them extensive updates, remember that XP is a very mature OS, now seven years old, and Microsoft is trying to sweep it under the rug as quickly as possible. Still, an SP is an SP, and I'll take it. I'll have hands-on coverage as soon as possible.