There is a patch day coming real soon now. I have no idea how badly (if at all) this patch will affect existing addons. However, it is time to think about how you are going to update your addons, or how you might live without them. We have had issues in the past.
It appears that Wowstead, wowpedia, Arena Junkies and Curse, Curseforge, MMO champion are all down, as well as many other websites.
Historically I have used curse, as a convenient way to update the majority of my addons. However, there is another repository of addons at www.wowinterface.com. (Yes to Johny up the back - I know you write your own addons, or at least ring up the authors and get them via carrier pidgeon - I like a central repository that makes it easy - and anyway curseforge is down too.)
The most usefull page I have found for a status update is at www.curseforge.com, at the time of this (updated) post contains
CurseForge is down for emergency maintenance, we apologize for the inconvenience.
Update 18:30 UTC / 1:30 pm CST: Faulty hardware has been replaced, we are in the process of verifying data and expect to be back online in the next 60 minutes.
Update 19:40 UTC / 2:30 pm CST: The data verification is taking longer than expected. We have no new ETA at this time. Update 23:45 UTC / 6:45 pm CST: Unfortunately, the data verification and restoration process is taking much longer than initially expected. Our current estimate is 6 hours to complete the process.
Update 06:30 UTC / 1:30 am CST: Data verification is 55% complete. As we cannot accurately estimate the time it will take to complete, we cannot give any further time estimates until this process is complete.
Update 20:45 UTC / 3:45 pm CDT: Data verification is still underway, but progressing very slowly. We will post another update once we get close to the end of this step of the process.