It's really going to depend on the format of your video.... but if you can convert it to flash (flv) format then I would recommend that you have a read here:

swfobject - Project Hosting on Google Code

You may also want to have a look at Amazon's S3 service for the actual hosting of your video:

Amazon Simple Storage Service (Amazon S3)

I guess it depends on the nature of your site, and what you are trying to do. IE has always been behind the eight ball when it came to keeping up with standards, (that nearly every other major browser supported) as a result developers have to create work around so that pages display correctly in IE. This holds true for HTML5, here what you need to do if you want to work with HTML5 now as described earlier in this thread...

Add this line of text to the head section of your page:

<meta http-equiv="X-UA-Compatible" content="chrome=1" />

I won't bore you with the details, but google "Chrome Frame" if you want to learn more. This work around what developed by Google to allow developers to use HTML5 in IE 6 and up. There are critics to this method, but at the end of the day even when IE9 rolls out there will still be tens of millions of users using IE 7 and 8 look at how many people are still using IE 6 today...

I guess if you are just a end user then you can wait for IE9 to come out before you start messing with HTML5. If you are a developer you will be WAY behind the eight ball if you haven't stated working with it like yesterday. Not that you can't get up to speed fast - because you can...

I have several sites live now using HTML5, when it really does go main stream I will be in a great position as a freelancer. If you look it is actually being used all around us. Mike Filsaimes AffiliateDotCom.com site is coded in HTML5.

HTML5 comes down to 3 things, if you work with these 3 things you can create web vodoo magic:

1. HTML
2. CSS
3. JavaScript API's

It the combination of those 3 that make HTML5 what it is.



Jay

Easy Video Player is what I have been using for this. Makes it pretty simple and integrates well with Amazon S3. You have a choice of different players as well.

Just a heads up-- if you plan on doing any Facebook advertising, you can't have your landing page have a video which autoplays.

Has anyone tested if the autoplay results in more conversions? I guess it must work since it is so common.

I personally don't like autoplaying videos without controls. You are bound to annoy some of your visitors. (They like controls.) People browsing on the job when they are supposed to be working might get caught. I guess they learn to keep their speaker volume off.