Google and Apple couldnt be more different. Googles revenue comes from Advertising, Apples from Hardware, software and more so recently content be that music, apps or soon media. Suddenly Adwords seems so old school. During the naughties the Apple juggernaut has carved a huge new market with way more potential than advertising.
So Google are developing a tablet operating system. That's great for competition. The problem is that Googles operating system hasn't got the existing developer base an thorough bread lineage which the iPad has.
The iPad uses the iPhone SDK 3.2, already years old and solid. The iPhone OS is Cocoa Touch, a derivative of Cocoa which Snow Leopard is built on. What I mean to say is that the foundations upon which the iPad are built are stable, already proven and adopted by both iPhone app and desktop app developers.
Google are not going to gain much ground fast releasing a tablet OS. They are not a hardware company, they don't have the support infrastructure. Ask anyone who has tried to get support for a Nexus 1.
They are clearly crapping themselves at the lost advertising revenue browserless web access offered via iPad apps will mean. Apple are drawing people away from search in droves.The iPhone and iPod Touch have meant millions have experienced the browserless web and enjoyed a streamlined focused ad free web. The iPad takes it one step forward again and may just be the first real Google killer.