Are there any addons that allow us to middle click any link and open the link in a new background tab in Chrome?

Sure is:

Open a link without loosing the current page!

The way I use it: left click - open on the spot, middle click - open in new background tab, right click - open in new foreground tab. middle click on bookmarks - open in new foreground tab,

Options: - configure Right Click and Middle Click to open links in new Background or Foreground tab; - remove target="_blank" from links (enabled by default). So there will be no more links that open in a new tab when left-clicked;

https://chrome.google.com/webstore/detail/afalkcagoidkdjdlfoaicbanbfgoamoo

Note that this bug is tracked at http://code.google.com/p/chromium/issues/detail?id=62319 and http://code.google.com/p/chromium/issues/detail?id=84514

The extension in Moab's answer does not work around the bug.

Star them if you want to see more traction towards a real fix.

There's a Chrome addon that does exactly what you want.

Fix middle click behavior for a lot of pages (also ctrl+left)

If you know a page where middle (or ctrl+left) clicking a link doesn't have the desired effect of leaving the current tab unchanged and opening a new one, this extension will most likely help you.

https://chrome.google.com/webstore/detail/ikbkhpkapkmhaoiabhlkmicpeakhhpip

I've used it for a while now and haven't found a site that it doesn't work on.