Yes. By default Google will provide a wide-screen version of the mobile site, but you can switch to "desktop view." However, scrolling doesn't work so Google adds a "Next Post" and "Previous Post" item to the bottom of the list.
Since both the PlayBook and the iPad share the same fundamental browser components (WebKit is an Apple production), I'm sure Google will only have to add the device sensing to add the next/previous buttons and they should work.
Personally I prefer the app Reeder (reederapp.com) because it's very fast and can syncs and cache images, so I can pull down my unread items at the office and catch up over lunch without having to turn on the tethering or find WiFi.
