[plt-scheme] R6RS Compliance?

Noel Welsh just asked about emerging conflicts between SRFI-1 and the
upcoming versions of PLT Scheme.  The R6RS standard also has a list
module which overlap with the functionality of SRFI-1.   Which reminds
me:  The PLT team did say that they intended to support the R6RS
standard in about "six months".   I'm not sure exactly how long ago
this was, and I'm don't really care whether or not there are any
delays.  I'm just curious whether progress towards R6RS compliance is
being made and would like confirmation that this is still planned.
Most of the recent changes and improvements to PLT Scheme seem to be
innovative features, rather than features aimed at complying with the
R6RS standard, or any standard.

I've been playing with Larceny and Ikarus, the only two R6RS Schemes
to my knowledge at the moment.  I have an application I would like to
port to R6RS before it is documented and published, as open source
software, and need to decide whether to start this porting effort
soon, with some other implementation, or wait until PLT Scheme
supports R6RS.

-Tom Gordon