The new Android software, which features the new Material Design, is already on the recently released Nexus 6 and 9. It's also now on its way to the Nexus 4, Nexus 5, Nexus 7 (both first and second generation), and Nexus 10. It will also be showing up on " Google Play Edition" devices. These include the Moto G and HTC One M8.
It's expected, but not certain that earlier Google Play Edition devices — the Samsung Galaxy S4, HTC One (M7), Sony Z Ultra and LG G Pad 8.3 — will also get it.
If you don't own one of these you'll be at the mercy of your device manufacturer.
Here's where and when you can probably begin to expect to see Lollipop on your device:
HTC has said that they'll release it on the HTC One M8 and HTC One M7 within three months of Google's release. You could see it by mid-February 2015.
LG hasn't announced any plans yet, leaving open the possibility of it landing on the LG G3 and G2 Pro in the future.
Motorola Mobility has been more forthcoming and generous. The first- and second-generation Moto X and Moto G, plus the Moto G with 4G LTE, Moto E, Droid Ultra, Droid Maxx, and Droid Mini will also get Lollipop.
Samsung has remained silent, but more often ahead of the curve than not, expect it will show up all of its 2014 devices. (Speaking as someone with a Galaxy S5 by his side, the sooner they get it out, the better!)
Sony's plans are to bring Lollipop to its entire premium Z series. It will take a while though. Sony announced that they'll start the upgrade at beginning of 2015 for the core Xperia Z3 and Xperia Z2 series and then bring it to the rest of the family.
I've been using Lollipop myself on my rooted Nexus 7 2013 for several weeks now and I quite like it. It's an update that I think any Android device fan will love.