NOT! Well not yet anyway, however I have this week been introduced to a web site that allows you to assess you IMBAness and recommends which pieces of gear, including enchants and gems, you need to look at upgrading.
The site I am refering to is Be IMBA! whose purpose, to use their words, is:
to guide World of Warcraft players to maximize their PvE effectiveness. The carefully selected checks and advisories help to identify common pitfalls and mistakes whether they are talent or gear related. We hope that our service presents a useful guidance for the casual and hardcore PvE player alike
The site queries the World of Warcraft Armory and wowhead.com for you character and gear information and makes recommendations accordingly. You do not need to register with the site but if you choose to do so you can force character data to be refreshed directly from the Armory, if not a cached version is used
Does being IMBA really matter?
TBH the answer to this question all depends on you, IMHO being IMBA is not worth sqat. So why am I posting about it then? I regularly do HC instances with a group of friend from my guild and we normally breeze through them, however looking at my DPS in recount I noticed that I was lagging severly behind my friends. No one had an issue with it but I don’t like to think that I’m not making a valid contribution or that people are carrying me. Chatting with my friend about the issue brought Be IMBA to my attention, so off I went to have a look.
It’s now only 4 days down the line but using the information from Be IMBA I have managed to take my DPS from ~900/sec to ~1,400/sec on average and have even started to have to pay attention more ot Omen 3 as I am starting to gain more agro 
This transformation has cost me roughly 500g most of whiich went on [item]Wispcloak[/item], I also got [item]Slithering Slippers[/item] and [item]Living Mojo Belt[/item] from HC Gundrak, [item]Prison Manifest[/item] form HC Violet Hold and [item]Sundial of the Exiled[/item] using Kirin’Tor rep.
Anyway don’t just take my word for it, check out the site and see for yourself
I’m a fan of Be Imba, if only because it makes it really obvious when I’ve got empty gem slots, or missing enchants. I like the way it suggests enchants as well. It actually made a big difference to my gear just getting the enchants and the gems right.
A similar site is http://www.wow-heroes.com although it doesn’t seem to play nicely with my Firefox so I’ve not played with it much.