Transformational Patterns?

[Pete Kazmier]

After reading the paper "Pattern Guards and Transformational Patterns"
by Martin Erwig and Simon Peyton Jones, I'm left wondering about the
status of transformational patterns?  Can we expect to see these at
some point in GHC?  Or have they gone by the wayside in favor of some
other alternative?  

When I had finished reading the paper, I was disappointed to find out
that they were not implemented as I was convinced of the merits based
on the arguments presented in the paper.

Thanks,
Pete

[1] http://research.microsoft.com/~simonpj/Papers/pat.htm