I definitely think so. If HTC and others can do well enough with their own Android phones, then Google is likely to sit back and let Android progress without any hardware from Google.
However, a gTablet is very likely given the stake Google has put behind Chrome OS. And tablets aren't necessarily something Google's traditional phone partners are likely to get behind. At least, not the way Google would like it done.
If that's the case, Google is more likely to introduce their gTablet. And more so if no one else shows interests.
And they would have to do it for two reasons. While Google is pushing Chrome OS as a natural fit for netbooks, it risks being "type-casted" as a low-end and no nonsense OS that is only good for e-mailing and browsing the Web. After all, Chrome OS is being positioned for the future where webapps is all that mobile users will need. Whether that actually happens to the degree Google foresees, only time will tell. With netbooks considered limited in capabilities, associating Chrome OS with it can paint it in a bad light.
The other reason is Apple will be attempting to create a market all to itself: A 10" tablet powered by iPhone OS runs on a combination of Webapps and standalone apps connected to iTunes. Google will need to move into this market to compete or at the very least, make sure its wireless mobile vision comes true.
And if white spaces networks (More on white spaces) ever come to pass, Google will need to have devices running on it and netbooks will not be enough to compete against Apple's almost certain to be popular iTablets. If it can convince someone like HTC or Archos to create gTablets, all the better for Google.
Google is watching the Android space closely. Learning from it. The key will be Android and Chome OS adoption. Standalone apps versus webapps. If Google can't make the case for Chrome OS and webapps, it will have no alternative but to enter the hardware market.
Personally, I love to see gPhone or gTablet. Given Google's traditional support for open source and open protocols, it can really make huge waves in the mobile hardware market if done correctly.
Bottomline: If Google wants Android and Chrome OS done right, it'll have to do it itself eventually. I'm betting a gTablet is more likely to happen.
Note: I don't want to portray this as an Apple-v-Google post. So far, I've not seen any mobile device that has evolved sufficiently beyond traditional laptops other than the iPod Touch. Perhaps, we'll see a whole host of such devices soon. There are some.
Archos devices are nice but limited. Nokia's N tablets hasn't really caught on. I'm hoping that Zune with the new Windows Mobile 7 will really shake things up in 2010 but it's not certainly that Microsoft has the vision to look beyond short-term marketshare gains at this time.