I think you're probably right for the low end market. The amount of OEMs that are going to be pumping out pretty good phones is huge and their are a lot of national brands in various countries that have signed up for building WP81 handsets.
Although, at the high end, even though the big Android players like Samsung and HTC are going to push out high end handsets I would bet the naming conventions they use are not enough to sway people.
What I mean is for instance Samsung sell the Galaxy, pretty much most people and their dog know that's their iPhone equivalent. Those same people are going to say, "what on earth is an Ativ?" and assume it's a lesser handset. Now if Samsung called it a Samsung Galaxy SW8 for example or HTC go with the rumoured HTC One W8 they are recognisable product names and as the price point for WP phones have historically been a little less than the high end Android phones I believe more consumers at the local phone shop might go for Windows.
I also think one trick Microsoft themselves are missing here with marketing, and it's the main reason I've never owned an iPhone or Android handset is that Windows phone at its core is a communications device, it may not have the apps and the big features but it's a rock solid clear and concise experience when your priority is making calls, texts, emails or using social sites and it integrates so well and in a way that neither iPhone nor Android (without third party apps or OEM customisation) can compete.