No - and this is the problem...
Directing you to a legacy desktop web app that is optimized for mouse/keyboard input is a huge elephant in the room for Windows 8 RT and IA (8 and Pro) right now.
It is a crutch. When I am in the Modern-UI gallery and I want to share a picture, and the options are Fresh Paint, Mail, SkyDrive, and Windows Phone - Microsoft has an integration problem with the maturity of their touch-oriented interface. Windows 8 needs to have *all* social media as integrated throughout the OS as Android and iOS, and right now, they're not even in the same ballpark. Windows needs stand alone Modern-UI apps for Facebook, Twitter and Google+ that meet or exceed what is available for Android and iOS, and in some of those cases, the decision to create an authorized 1st party app for those media services is outside of Microsoft's control. That could be a big liability for adoption of Windows 8 *outside* of professional productivity models.
Right now that is EXACTLY how I do things like sharing images or links or other information to social sites - I drop back into Classic mode and do it in a regular web browser. That works, and arguably having that flexibility can be an *advantage* (things that I wouldn't be able to do on an Android or iOS device until I got back to a "real" PC, I can do on one Windows 8 device, right then) - but it also doesn't offer the convenience or transparency of execution that mobile platform users expect.
It is one of the biggest obstacles to getting mainstream consumer adoption of Windows 8 as a single unified platform across their devices.
