What is ECMAScript Editon 5.1, and what is it for?

Question

I just stumbled upon this (while browsing the ECMA web-site):

http://www.ecma-international.org/activities/Languages/Draft%20Standard%20ECMA-262%205.1%20edition.pdf

It says here that edition 5.1 is going to replace edition 5 in June 2011.

My question is: What is this edition 5.1 and why is it being published? (Is something wrong with edition 5?)

Edit: I found this:

ECMAScript 5.1 is a maintenance revision of the ECMAScript 5 specification. It corrects technical and editorial errors and its content is identical to the proposed ISO edition of the ES5 specification. This is intended to be the final draft, subject to approval by TC39 and the completion of the ISO standardization process.

Source: http://wiki.ecmascript.org/doku.php

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Update:

As JavaScript Weekly posted in today's newsletter, ECMAScript 5.1 has been ratified and has been made available for download on the main page for ECMAScript here:

http://www.ecma-international.org/publications/standards/Ecma-262.htm

Answer 1

From http://www.wirfs-brock.com/allen/posts/39

The ISO edition of the ES5 specification incorporates a number of editorial and technical corrections including those listed in the current ES5 errata.

In other words, ECMAScript 5.1 is a revision of 5.0 that corrects some errors in the document itself. As mentioned later on in the article:

Keep in mind that this is only a maintenance revision of the ES5 specification. It contains no new language or library features. TC39 is continuing its longer term work on “ECMAScript Harmony” which is intended to be the next version to include any new features.