So I've decided to make it in "ViM way".
It's not a secret that icons in ViM can be easily customized. Reading :help toolbar-icon gives clear path to using your own customized icons. So, I took the file from char101 blog post and converted it into a set of 16-bit BMP files using Paint.NET. Here's the result:
You can get those bitmaps here just unzip the archive to your system/user vimfiles folder.Thanks to Mark James for great Silk icons
and to Char101 from http://charupload.wordpress.com/ for pointing me to those icons.
UPDATE 30/05/2012: Icons are uploaded to GitHub. https://github.com/istepura/vim-toolbar-icons-silk
