Well I found the answer, but no one will like it.
I pasted the text below.
Apparently the update for Office that came out yesterday is NOT the final version.
That means that today, you can NOT edit SharePoint documents.
Also, Microsoft is NOT saying if you ever will be able to edit them from Surface RT, only that "That we do not know - until the final release of Office RT, we are unaware of what features may or may not be supported as the list is constantly changing. We do not have a published list of changes at this time."
Tim M: Hello, thank you for contacting Surface Support. My name is Tim M. How can I help you today?
Chip Eckardt: I ran out of space so. I am using Windows RT, have installed latest Office Update
Chip Eckardt: I am connecting to SharePoint 2010 server
Chip Eckardt: The error message should be in first item I posted.
Tim M: Yes, I see the error message. The reason is that Office RT is not a full version of MS Office yet, it is still the Preview Edition, and as such not all features are active.
Chip Eckardt: but I installed the roughly 560 meg update last evening
Tim M: the final version of Office RT has not yet been released, it is still in preview or beta form. Updates are being released regularly to keep it up to date, but the final version has not gone live.
Tim M: One moment please while I research your question.
Tim M: At this time, it does not appear that Office RT will connect to Sharepoint documents correctly, this looks to be an issue with the Beta release which may be resolved when the product has been fully released. At this time, however, Sharepoint documents are not supported on Office RT.
Chip Eckardt: Will this be fixed shortly?
Chip Eckardt: I ask because if it does not work with SharePoint I will have to return my Surface--but I REALLY love it.
Tim M: That we do not know - until the final release of Office RT, we are unaware of what features may or may not be supported as the list is constantly changing. We do not have a published list of changes at this time.
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