Howdy,
The following is pretty much the "conversation" back from MSFT regarding this topic.
If a user wants to buy today and be automatically upgraded to the latest version of Expression Studio when it ships then they need to purchase Expression Professional Subscription (EPS) – this is the recognized and supported way for someone to receive an automatic upgrade once a new version ships.
For individual product purchases historically Microsoft hasn’t offered grace periods. Once a product is purchased there is no automatic upgrade unless a customer has purchased Software Assurance – which essentially is one of the benefits EPS provides. So if someone purchases Expression Studio 2 today (or or an individual Expression product) to receive Expression Studio 3 they will need to purchase an upgrade.
You may remember last year we did run a grace period offer where people could purchase an Expression v1 product then upgrade for free to v2… this offer was run as a one off deal to our customers as EPS wasn’t an available purchase option at that time.
I advise you to make some calls or send some emails to the people you deal with when purchasing MSFT products like this so you can be assured that you have the protection required. The information provided in this post is a "quote" so take it as that please. It may not be used as a legal statement from Microsoft.
HTH
Cheers
Expression MVP
my blog : http://x-coders.com/blogs/sneaky/default.aspx