Curse

I'm glad to help.  Though, I don't have many folks providing feedback on the classes (as requested for the last 2-3 weeks).  So, the updates will eventually stall (and have begun to already).

I really need people to provide the feedback as indicated in the mod feedback link.

I have the ability to communicate with Gagorian outside of games or forums.  After all, I did help him get his WoW account reactivated. :)

In any event, he's been on (for me) a lot sooner than March 6th.  We discussed some weird wow mechanics and how to implement a few things we needed to get done.  Nonetheless, my last communication with him (after March 6th) indicated there was no change in the status of the Ion addon integration as he hadn't heard anything from the author.

Though, keep in mind that Ion support is lower on the list of priorities.  Higher on the list is to make sure all classes function correctly.  (Which is not relevant to custom UI integration since the addon works with the supported ones or with none.)  This will hit the widest number of people than stalling a project to wait for the addon author to respond.  This is why I ask for feedback on the untested classes/specs - as it affects the widest number of people at once.  

Monks are next on the list, but they're in a waiting pattern until information about established classes is provided.  This class requires a brand new module which could completely break or fail to function - whereas most of the other classes are modifications without a rewrite.

So, I must reiterate, if people want the addon out of alpha state, more testing is needed.  See the website for more details.

Well, it works with the supported addons just fine. I happen to use ElvUI without issue (and a number of other users use the other supported ones or none at all).

Regarding Ion, we do not support it for a good reason.  Gagorian emailed the author requesting technical details regarding integration.  However, as of 2 weeks after sending the request, the author had not responded at all to Gagorian.  Without proper details regarding integration, we will not do it.  The structure is NOT the same as the original addon (Macaroon).  As such, improper integration is worse than no integration.  

(Edit to add:  The Ion mod details request was made back in February, by the way.  And, as of this date, that information hasn't been received. This information is also included in the "Known Issues" link in the Wiki on Curse and has been once the question was asked.  This update to the wiki occurred March 6th. (I made the change myself when the question was asked.))

You can give feedback without that addon if you want.  But, utlimately, the choice is yours on which one takes precedence. We cannot and will not make that choice for you.

Edit to add this as well:  We had someone other than the mod author post a partial and buggy patch for Ion support.  Gagorian was specific on this:

"Yes I looked at it and had already earlier figured out what he suggested, the problem is the buttons aren't updated when new buttons are created or spells are moved.. if we'd add a buggy solution like that, next thing there would be a million tickets of Ion support not working correctly."

" I already messaged that guy that I wont use it before the solution is complete."

Right now, the only class that isn't implemented at all is monk.  Other classes may be inaccurate (mostly only a few specs like Discipline due to last minute 5.2 changes) but otherwise mostly functional.

See the current status on the known issues page.  Follow the mod feedback link to test and see how to report bugs/issues.

Update 4/01/2013:  I still need testing for the listed classes.

1.) Paladins (all specs)

2.) Enhancement shaman

3.) Assassination Rogues

4.) Resto druids

5.) Balance druids

6.) Warriors (all specs)

7.) Shadow priests (aqCelestyna@wowace has helped some on this)

8.) DKs (all specs)

9.) Hunters (all specs)

Please follow the known issues and mod feedback links on the wowace site.  So far, I haven't had anyone willing to provide this feedback at all (despite indications that folks were interested).  Less feedback means a much longer period of time to get this into a beta/release state.