[X]HTML custom tags: pros & cons

[madix2]

I'd like to use some semantic [X]HTML tags instead of \[code\]<div>\[/code\]s: \[code\]<article>\[/code\], \[code\]<product>\[/code\], \[code\]<footer>\[/code\] etc. Some of them are already presented in the upcoming HTML5, however, it's not fully supported.Which are the possible cons I might face when Rendering? Using CSS, JS?The one I remember is: IE6 can't clone tags it doesn't know.