Microsoft has never been able to copy Apple well, even when it has tried. Just look at their OS and UI. And I think the same thing will happen in these stores, in spite of how accurately the designs emulate Apple.
IMO, in some respects, this could hurt Microsoft more than it might help: it could reinforce the notion that Microsoft is a "me too" company who has to copy Apple, the leader in innovation.
Also, if the final execution does not have the quality of Apple's stores, it could wind up looking like a cheap copy - like a chain restaurant's "emulation" of a high quality restaurant. (Reminds me of the time I was in a chain steakhouse and they served Lancer's wine in a plastic bottle, but still let the purchaser sample the wine to see if it met his "standards".)
Having said that, if these Microsoft stores become more prolific than Apple's, that's what consumers will go to -- sort of like the way people shop in Radio Shack--it's because "it's there." And if the stores do manage to look just like Apple's, it might lead many consumers to think that Microsoft is just as good, which is probably the intention.
In the current economy, Microsoft can probably pick up cheap leases, which would be to their advantage. In the long term, this is a very expensive exercise, especially for a company that doesn't sell computers.
What will be more important than the look of the store is how it operates. If there are a lot of locked up applications on the demo machines, that will be a problem. If access to the internet requires a password, as it does in most chain operations, that will be useless. If they want to succeed, they have to create as much of a destination as the Apple stores seem to be.
What will be interesting to see is how Microsoft picks their locations - will they attempt to be on the same street and in the same mall as every Apple store?