Switch your document library  to "explorer view" - then you should be
able to do this

If you open your SharePoint document library  up in "explorer view" you
can drag multiple  documents into it.

You can also use WebDAV. This is easier than you might think. In Windows
Explorer:
1. Choose My Network Places from the treeview on the left.
2. Unselect the Folders button in the toolbar and the treeview should
become a list of possible tasks.
3. The link to the first task in the list is to Add a network place;
click the link.
4. Walk thru the wizard to create a link to a Network Location (not an
MSN Community).
5. Provide the URL (including the http protocol) to either the site or
the root of the specific document library  that you want to access.
6. Give it a name that will help you remember what that location
represents.
7. Finish the Wizard.

Now the contents of the sharepoint  location that you choose will be
available as a choice within My Network Places. You can use this just
like any other local or mapped network resource in your network. You can
copy files  from or to WSS document libraries from within Windows
Explorer at will and just like you would if the source or target of your
copy/paste was another file system  location. Microsoft facilitates this
interaction using WebDAV.

Is there anyway to go beyond the 2GB upload limit?

I suspect that is a hard limit imposed by the database type. Of course,
the HTTP transport is a good deterrent to larger files  too.

You can also change the max upload size in central admin and choose to upload
multiple files

WedDAV seems to bypass the enforcement of otherwise mandatory metadata,
is that correct?

In v2 it did not enforce it. In v3 I think that it does, but I haven't
tried.