Returning to onlineAccount > OnlineAccount

After some off-list debating with Thad Guidry, Aaron Bradley, and some
other folks, I'd like to try to get (social/online)Account >
(Social/Online)Account back on the table again.

After reading most of the previous discussions about this topic, as well as
taking FOAF into account, I'd like to suggest a new property, namely:
onlineAccount
domain: schema.org/Organization and schema.org/Person
range: schema.org/OnlineAccount *(=new Type)* and URL

onlineAccount > OnlineAccount:

<div itemscope itemtype="http://schema.org/Corporation">
    <h2 itemprop="name">Acme</h2>
    <ul>
        <li itemprop="onlineAccount" itemscope itemtype="
http://schema.org/OnlineAccount">
            <a itemprop="url" href="https://plusbook.com/AcmeCorp
">PlusBook</a>
            <link itemprop="provider" href="https://plusbook.com"> (which
could also be markup that describes the entire organization)
        </li>
    </ul>
</div>

onlineAccount > URL:

<div itemscope itemtype="http://schema.org/Corporation">
    <h2 itemprop="name">Acme</h2>
    <ul>
        <li>
            <a itemprop="onlineAccount" href="https://plusbook.com/AcmeCorp
">PlusBook</a>
        <li>
    </ul>
</div>

I suggest naming the property 'onlineAccount' because of the added meaning
of the adjective 'online'. If we'd use 'account' like FOAF does, IMHO the
property name would be a bit too generic, eg: account > URL stil doesn't
say much about what's to be expected at the given URL.

As for OnlineAccount, again IMHO, this could perfectly well cover things
like Github, Facebook, Pinterest, and what not more. But in case there's a
desire for more specific types of Accounts than we can also consider adding
schema.org/Account of which OnlineAccount would be a subClass, as well as
any other possibly needed subclass.

Lastly I suggest we use 'provider' to express the relationship between the
OnlineAccount and it's service provider - FOAF's 'accountServiceHomepage'
just seems like too much of a hassle to me.   ;)

And as for the whole inverse property issue, since it looks like adding
@itemprop-reverse to the microdata specs will take a while, I suggest we
add an 'accountOf' property to schema.org/OnlineAccount, to work around
that issue, eg:

<div id="AccountOf" itemid="#AccountOf" itemscope itemtype="
http://schema.org/Corporation">
    <h2 itemprop="name">Acme</h2>
</div>

<ul>
    <li itemscope itemtype="http://schema.org/OnlineAccount">
        <a itemprop="url" href="https://plusbook.com/AcmeCorp">PlusBook</a>
        <link itemprop="accountOf" href="#AccountOf>
    </li>
</ul>

How does this sound?

Oh, and any thoughts what OnlineAccount's (or Account for that matter)
superClass should be?