Nexus 7 is great. But there is so much distance between Android and Apple in tablet market share right now. I doubt it'll be the Nexus 7 that will lead Android tablets in eclipsing Apple tablet market share, but maybe the a later Nexus tablet.
But Nexus 7 is probably going to give Android a good kick start in that direction. Samsung, Motorola, Toshiba, Lenovo, just about everyone has been really disappointing this year. Only bright spot seems to be ASUS and maybe Acer. This the Galaxy Tab 2 suppose to be a weird joke I don't get and the Galaxy Note 10.1, WTF Samsung?
Apparently Google and ASUS have to do this on their own, because the other Android tablet manufactures really aren't doing a damn thing right now.
I am not discounting Microsoft either. I don't have any plans on getting a Windows 8 tablet, seems like they'll be too expensive with almost no real tablet optimized apps in the beginning. But they are tying their tablets tightly with Windows and Xbox though and who knows what impact that'll have.
PS. And Google hopefully will have a Nexus 10 out this year. 7 inch tablet is nice. But unfortunately I'm not selling my iPad 3 until I have a 10 inch Nexus tablet (or maybe a Transformer Infinity with Jelly Bean and the fixed IO issue).