The whole point in WP is its interface. Metro is akin to WP/Win8 devices as the iOS is to Apple devices. It should never be changed. Microsoft have spent a lot of time and money in getting it right, if they wanted to let OEM's continue to customize, they needn't have bothered, and instead just finished Photon instead of ditching it for WP.
If the likes of HTC arn't happy, then screw them, HTC and Samsung are for the mostpart, boring, every HTC device seems to be a copy of the last, and every Samsung device is an iPhone wannabe.
I'd hazard a guess that Nokia will have sold more WP devices by the end of 2012, than the rest of the manufacturers combined since 2010... if not already. Microsoft does not need HTC and Samsung as much as they want to be involved in the WP party. If the unthinkable happens, and either Blackberry and/or Sony move across to WP (the more marketshare they lose, the more likely it is to happen, having seen how Nokia's fortunes are improving, remember there is already speculation that BB may be interested in selling off it's consumer division) then it could just about finish Samsung off in the WP fold anyway, and see a role-reversal of the current trend, with the former "big boys" climbing back up the marketshare ladders. It's all theoretical of course, but it's possible.
Android is not the powerhouse many people see it as, it is doing NOTHING for Sony and never has done, in fact the original HTC built Xperia's running WinMo seemed to have more going for them than the current range. Android does well for Samsung, and 100+ devices a week HTC, iOS obviously does well for Apple, and WP is rebuilding Nokia.
The likes of Sony and LG will only continue to lose money for so long on Android/mobile divisions, before they jump behind WP full-throttle, or drop out of the market. Unless they decide to take the risk of the century and develop the now open-sourced WebOS, which isnt too unfeasable, though the shareholders may not allow it.
Besides which, any device manufacturer, should realise that WP is a much better interface than anything else out there, and should be made up to see the success Nokia is having - because they all share the same interface, it is effectively free advertising for other handsets. The problem I think they are having atm, is that Nokia are cutting their own throats with pricing atm, in a bid to regain a stranglehold on the market; nobody with a successful Android division, is prepared to do that.
Regardless of all this, Microsoft arn't much bothered by manufacturers choosing Android, they have the biggest mobile phone manufacturer in the world, as an exclusive and fully-committed partner, and are creaming off money every time the likes of Samsung and HTC sell a handset... without having to do a moments work!! So the more Android handsets are sold, the better for Microsoft. The only reason for them bothering with WP is imho, to save face, and show the world why they are the best software developer on the face of the earth - the whole WP fiasco is more of an exhibition and bragging rights winner than a money-maker for Microsoft I think!! Every penny they lose, they make back on sales of Android handsets. Nifty business acumen.