Ad Hoc Indexes

Question:  We have recently moved PostgreSql as we just migrated to 
OpenMfg.  i really like the database and PL/pgSQL its very similar to 
how FoxPro language layout so learning has been pretty easy.

Now for my question It does not appear PostgreSQL does not have an Ad 
Hoc Indexes ability where the Query planner will create an in memory 
index based on the Select, Update, Insert or Delete commands.  I got 
pretty lazy with MsSQL and Foxpro doing ad hoc indexes to speed up 
complex queries where i should have created an index but never did.

Is there any plans in the future to add the ability for PostgreSQL to 
create Ad Hoc indexes if it makes sense.    Example i was creating a new 
report thats presently only processing around 120,000 records in the 7 
tables for the query. But the query took between 18 to 19 seconds to 
run.  I analyzed the query and added 2 indexes and drop the processing 
time to 93 milliseconds.
This query will be run 3 to 5 times a day so it makes sense to create 
indexes

But with reports that run maybe once a week or once a month it does not 
make sense to create indexes.  this is where I think Add Hoc indexes are 
nice to have because to my understanding maintaining indexes can get 
pretty expensive. 

Whats the likely hood of Ad Hoc Indexes being added to PostgreSql

thanks