Whats good about Android is that you can have latest features even on unsupported devices in the form of apps and tweaks. Google released Android L factory images for Nexus 5 and Nexus 7 about a week ago and developers are already coming up with Material design inspired themes and applications. We already have CyanogenMod themes inspired by Android L, and today, developer Shen Ye ported the official Android L keyboard for devices running Android 4.0 or above.
The keyboard comes with the same settings as that of Google Keyboard, but its design is inspired by the Material design in Android L. And since it is taken from the Preview build and modified to support Ice Cream Sandwich or above, the app features the same look and feel of the official Android L Keyboard.
After downloading the app from Google Play Store, you just have to follow the on-screen instructions to set it as your default keyboard app. To do it manually, you can head over to Settings, then to Language & Input, then under Keyboard & Input Methods, you have to check the Android L Keyboard option and then select the same in the Default keyboard. Once done, you will get this new keyboard for typing.
You can select desired Input language, and enable or disable options like Auto-capitalization, Vibrate on keypress, Sound on keypress, etc. Basically, it covers most of the Settings of the current Google keyboard app.
Android L Keyboard app is free on Google Play Store.