Version 4 LDAP particulars?

[Jim Hogan]

First, my deepest gratitude to the Samba Team.  I'll try to be brief. 
Don't want to rob much of anyone's time and am almost embarassed to pose 
my questions here.

Situation: We run 3.10 today in simple domain model with tdb auth, but 
have need of LDAP for many reasons.   I see LDAP noted as "non-release 
delaying" feature for Samba 4.  We do not have any urgent need of AD 
support in Samba 4, though some "subfeatures" could be useful (group 
policies, say?) if they wind up as part of V4 AD feature set.

So, I am trying to evaluate "Build OpenLDAP directory today and 
integrate with V3 or perhaps wait...or take some hybrid approach?"    I 
looked at latest latest LDAP source from subversion and see what looks 
like scratch-built LDAP server.  So my questions:

- Will Samba 4 still allow substitution of existing OpenLDAP/other LDAP 
service for ldb support?
- Can anyone point me to V4 default LDAP schema in source?  I probably 
need a dope slap but couldn't find it.
- To ease later migration to Samba 4, could v4 schema be applied to 
build a v3 (OpenLDAP) schema for ldapsam support?
- Is the Samba 4 LDAP server planned to be generally useful (support 
Linux sign-on, http/Apache/PHP auth in our case, say) or are there any 
specific expected limitations?
- Is LDAP really non-release delaying?  If ldb is required for Samba 4 
operation, how can that be?

I'm not sure if it comes through in my questions, but the notion of an 
all-in-one Samba+LDAP is pretty exciting.  The team's track record is 
awesome and I am in awe of what you've all done.  Like probably a 
billion others, I am intensely interested in progress of Samba 4, but 
know that most things are done when they're done.  I just have to figure 
out the smartest course in the short term.

My apologies in advance if some of these questions were answered 
elsewhere.  My *thanks* in advance for your time!  Any other stray 
thoughts appreciated.

Jim