WoW patch 3.1.3 is going to be released soon and now it’s really close, being scheduled for tomorrow, according to MMO-Champion. The game will not get any major changes, probably, and it won’t happen until patch 3.2.0. Please note that the initial patch notes will not show up in the PTR, but we will let you know what the changes will be a bit later.
We’re thinking today will be the day for Patch 3.1.3 to hit live servers, so we have the full list of patch notes for you. It’s just a tiny patch but it is bringing with it some hefty downtime for certain servers. We have also listed those! Word is coming through the grapevine that patch 3.1.3 will be released tomorrow. MMO-Champion is also confirming this, so given both of these sites information WoW.com would say it's a sure bet.
From what we heard there would be wotlk patch 3.1.3 that will be released tomorrow. Although this news is not confirmed yet, however given same news from WowInsider and MMO-Champion would be this info is legit. This patch is mostly class balancing and some Ulduar changes.