IE12: Support for javascript and compatability mode

Hi,

We are developing a web application that is used across different versions of IE (9, 10, 11).

There are some news that Microsoft will be launching IE 12 in 2014. To make our application work smoothly in IE12 as well, we need answers to some questions below:

1) Will there be complete support for JavaScript in IE12 as it is present in IE11 or will it be reduced in any way?

2) To fix some compatibility issues in IE11, we are using the below tag in our pages:

<meta http-equiv="X-UA-Compatible" content="IE=5" /><o:p></o:p>

We need to know if this tag will work fine in IE12 as well.

3) Please confirm if there will be backward browser compatibility present in IE12?

4) If possible please let me know the tentative release month for Internet Explorer 12, so that we can plan our development schedule accordingly.

Thanks,

Nilanjan