Cross-browser support is added in Polaris and Update Rollup 12 for certain versions of Firefox, Chrome and Safari as described in this article http://support.microsoft.com/kb/2784954
A specific Ipad client is not planned for the Polaris release though it is planned for a release later this year.
Refer to this article on Technet with regard to JavaScript and other browsers http://technet.microsoft.com/en-gb/library/hh771584.aspx#BKMK_WriteJavaScriptForMutlipleBrowsers
When viewing reports, there are issues with print and zoom in browsers other than Interner Explorer. These are SSRS issues and are described at http://msdn.microsoft.com/en-us/library/ms156511.aspx