Your poll is interesting, it is like asking which graphics card is going to grab more marketshare, the Voodoo 5, GeForce 6800GT or AMD 4870. You are comparing parts with wildly different market timeframes for the mobile sector. Also they cross some very different markets themselves- two of the parts are best suited for Netbooks, passable for tablets and way too power hungry for phones(Intel would disagree- but 50% more power draw then Tegra2 is crazy in this market); one is borderline smartphone/tablet, the other is a mid tier smarthpone chip and weak tablet offering. By the time Ontario is shipping in anything- A4 and Tegra2 will be entry level smart phone parts.
Looking at it from a long term perspective in terms of their respective companies- Apple is already holding down a considerable marketshare and is rapidly moving up market segments with their parts. They have gone from a very solid showing in the smartphone segment up to a very impressive launch in the tablet segment. Apple has one huge advantage over the other three here, they make their own software for their platform. They also have a massive disadvantage compared to the other three here, they make their own software for their platform. In end effect, it is hard to imagine the downside not being too much for the upside to handle in terms of long term custom retention. That said, they had what it took to get their platform off the ground.
nVidia has already made a huge mistake in this segment. They focused their efforts on a third rate company with no clue how to compete in this market segment, a small time bit player named Microsoft. They realized how stupid that choice was at this point and have jumped on the Android bandwagon. If they could get RIM to support them too, they would be in a very good position to advance their platform moving forward. As of right now Android has all the market momentum, but this market can change very quickly as we saw with Apple's rapid explosion and now their steady decline.
Intel bet on MeeGo. Really, what can you even say about that? At least with nV you could understand that MS was bound to get it right at some point, even if it took them far too long(hasn't happened yet, but WM7 is a step in the right direction). Also, x86- really? Why burden yourself with an architecture that heavy? It's like they are trying to help everyone else spotting them die space to compensate for their fabrication advantage. This is the mobile market. ARM owns this market- why carry over legacy hardware? Clearly Intel had people in charge of Moorestown that were comparable in capacity to those in charge of Larrabee. If Intel doesn't rapidly make adjustments to focus on a viable platform, they are dead in the water. MeeGo is a fail.
AMD is likely 18 months or so away from shipping products to end consumers. The mobile market isn't like other markets, you don't release a chip in January and have products shipping to end users in January, or March, or July. On a realistic basis Ontario is going up against Tegra3, A5, and Moorescity- hard to say how it will do as none of the players that want to sell their current products are telling us about what is going to hit next year.
In the Netbook segment Intel and AMD should do quite well. Once you get into the smart/superphone/tablet category the problem is you need your part shipping with a viable platform. This is nothing at all like PCs where you make sure you run Windows better then anyone and you win. Intel/AMD and nV need to get up to par with platform support or they need to make RIM an offer they can't refuse.