Analysts also want to see Google integrate Android with its desktop OS, Chrome -- or, said Enderle, to get rid of Chrome altogether.
"There were a lot of questions [from developers] at last year's I/O about the merging of Chrome OS and Android, and those questions went unanswered," said Brian Blau, a Gartner analyst.
Milanesi saw advantages in both operating systems and thought Google should not force consumers to choose. Instead, they should have the "aha" moment of recognition across devices that they increasingly get from Apple's Mac OS and iOS.
Analysts said they will also be on the lookout this week for possible new features on Google+, upgrades to Google Maps and improvements to Android security.
This year's Google I/O, which sold out in just 20 minutes, will be the first to fill three days of programming. In response to the demand, Google plans to double the number of sessions it will livestream from San Francisco and put on 350 I/O Extended events, or conference viewing parties that sometimes host a keynote of their own.
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