Microsoft tries to improve web standards support in IE8 apparently...well, except for...
Known issues we are not planning to change in IE8
<OBJECT> is not parsed in a cross-browser compatible way (parsing stops at the OBJECT, whereas other browsers continue parsing all the fallback content and make it available. No support for this parsing behavior is planned for IE8; I'll take this opportunity to ask for real-world scenarios that can help me prioritize this feature.
<OBJECT> elements cannot be 'reactivated' by dynamically correcting the attributes that caused the original fallback. Again, your feedback on the potential benefits/use-cases for this feature appreciated.
With a goal to get the web browsers of today to become more interoperable, the ACID2 test has proven itself valuable. Microsoft recently claimed IE8 would correctly render ACID2, although lately there has been a bit of buzz on what that actually meant. Ian Hickson has started the work on ACID3 and with the competition for test additions being over now, I hope we'll see something more finished soon. A number of SVG tests have been added to the work-in-progress ACID3 test as a result of the competition (see tests 68 - 75).
So lets hope that ACID3 means that non-standard behavior will start to corrode away, resulting in a solid interoperable core of the web that, among other things, includes SVG.
Update: Here's the link to the submission that was made, note that the tests were partially rewritten by Hixie for the official ACID3 test.