Microsoft doesn't sell a product, it sells a component. It's the OS that OEMs buy when building their products. If an OEM wants to build a low-end, high-end, or vertical-market product using Windows, Microsoft will gladly sell them the OS and let the OEM take the business risk. Some will succeed and some will fail, but all will pay their license fee.
The only high-low positioning that Microsoft tends to do with Windows is the myriad "editions" which everyone tends to dislike anyway.
Unless Microsoft will produce their own hardware for a Win8 tablet, I think we are going to see a whole slew of tablet models with varying (and sometimes dubious) build quality. Like it or not, the iPad is pretty well put-together - I think that the tablet manufacturers are really going to have to scramble to compete on the hardware front.
I actually think that Win8 has some potential as a tablet OS, although my experience with the developer preview on a PC was a little underwhelming.
The standardization of iOS devices is what makes them so easy to use and develop for. Microsoft has done a good job of making Windows behave in a standard manner on diverse hardware configurations on desktops and laptops, so we can hope that WM8 will be equally standardized across different hardware. That would at least give them an advantage over android, and if they don't drop hardware support at certain versions they might be able to take over slowly when the cost of WM8 tablets drop below the cost of an iPad.
The trouble isn't the branding, it's the building. The iPad is recognized as a quality product because it delivers quality experiences.
Microsoft has rightly acquired a reputation for brittle products that will slowly break down in ways you don't know how to fix. "Microsoft" means worrying about obscure error messages, malware, backups, defrag, task management, ad nauseam.
They've made solid incremental efforts with Windows releases, and Windows Phone 7 may well have eliminated all of these experience issues. Trouble is, Apple has now all but eliminated these problems across the entire product line, and they've even solved the meta-problem of tackling the remaining problems through their world-class retail and support presence.
A solid product in isolation doesn't cut it at this point. The competition has a solid complete ecosystem. Amateur hour is truly over.
On a related note, I think that Microsoft and OEMs would have a hard time overcoming consumers' perception of the iPad as 'sexy' or 'luxurious'. Apple's had the head-start to build this sort of brand recognition for the iPad and IMHO, I fear that any attempts by OEMs to budge it will appear 'cheap' (quality-wise) or imitative.
Take the laptop market for example. Some attempts have been made at a sleek design that rivals the Macbook (HP Envy, Dell Adamo etc) but those products haven't really taken off.
As for the software and OS? I really like the Metro interface - I guess we'll have to wait and see how it turns out with regard to the app library and user experience.
If they think their product is better, then sell it as such. Actually say your product is better and therefore, it's going to cost more.