The Minority website has details on preorders for the PC edition of Papo & Yo, which are now underway. They have links to where to preorder, which carries a 10% discount and entitles purchasers to a free copy of the game's soundtrack. They also offer a FAQ which explains how this will differ from the PSN version:

Purchasers will be delighted to find the following upgrades:

• Better graphics and new visual effects
• Improved controls
• Improved character animation and cinematics (including some facial animations)
• More robust gameplay – lots of bugs fixed
• Full controller support for Steam Big Picture mode
• Multi-monitor support