But I do hope, and feel, that WP8.1 will support pretty much all chipsets, like Nvidia's and Intel's mobile chips.
Already two years ago many people wondered if something like this would happen, particularly due to repeated reports that ST-Ericsson had scored a contract with MS, that would end Qualcomm's reign as the exclusive supplier of chipsets for WP devices. I said it then and I'll say it again... its not happening.
Firstly, incorporating support for a new chipset occupies a large engineering team, easily for over a year. No matter how that work is distributed, that team is ultimately not working on things that would be far more important... things like closing the feature and functionality gap with iOS and Android. Considering all the catching up still required, and that MS can't rely on third party developers to the same degree iOS and Android can, the last thing we need is for MS to invest even more resources into low level software engineering that enables WP to do absolutely nothing new nor fundamentally better (just the same things either a smidgen faster or a smidgen slower, depending on what the actual task at hand is).
More importantly, this introduces major hardware fragmentation, which goes against MS' strategic goal of hardware standardization. Dropping that strategy would result in developers having to expend far more effort into keeping their apps compatible and working well within a far more diverse hardware ecosystem. WP is already behind in the apps race. We don't need to make it harder for developers. Android developers are willing to make that effort because the market is huge and the costs can be recouped through volume. Make it just as costly to develop for WP, and you can say goodbye to many a WP developer, particularly those that try to deliver games.
The goal should be for WP to support as few different hardware configurations as possible, without falling behind in the specs race. Unfortunately, MS hasn't been too successful in that department either. However, the problem is
not that MS supports too few chipsets, but that MS isn't ready to support a chipset when they are released. Android devices with said chipset are usually available up to six months earlier. By the time WP devices with that chipset arrive, it's already considered old news. Adding support for yet another chipset, likely just as late or even later, will do nothing to address that main problem... in all likelihood it would make it even worse.
Anyway, WP will support the S805 this year. There is nothing Tegra can offer over Snapdragon that would make the required effort (by developers world wide) worthwhile.