OK, so I'm reading ALA (A list apart) on the latest new thing to come out of the web standards group, something Microsoft intends to implement in IEv8. One of the biggest issues we web developers face in developing web pages is the varied version of browsers and code compatibility. If you look at the offerings here at CMX, you will find, from time to time, articles that address this in some manner (as in, for IEv6, you need to include; for Firefox, include; for IEv7 do this and for IEv5.x, try this - oh and Safari v1, just give it up). The proposed idea is to implement a meta tag which allows you to specify the browser engine to render the page with - for example, if you specify IEv8, when IEv9+ comes out, it is rendered with the same, prior, version of IE, v8. The goal of the standard would also to be allow multiple browsers to utilize this same functionality so that Firefox, Safari and the rest could also use this to render pages in prior engines for their product line (so I could specify IEv8, FFv2 and Safari v3, for example). The implementation will look like:

<meta http-equiv="X-UA-Compatible" content="IE=8" />

The articles went on to talk about the prior attempt to have web pages rendered differently using the doctype declarations. Both articles are a good read (not so much on the comments to the articles). It is my opinion that this is a good thing. I believe it will allow us to create a work on the web and not have to freak out when the next version of whatever comes out, worried our sites will break. I also believe it will aid us in transition from one browser to the next. Likewise, I have a couple concerns as well - how well will the future browsers render prior versions? and if I have a site created for IEv9 and you have IEv8, what happens? The articles from ALA are:

Beyond DOCTYPE: Web Standards, Forward Compatibility, and IE8
From Switches to Targets: A Standardista's Journey