Pre-set Hint bits/VACUUM FREEZE on data load..?

Greetings,
 In a discussion which came up at PgEast, I questioned if it'd be possible to set the 'all visible' hint bit and give
thetuples the frozen XID when loading data into a table which was created in the same transaction.
 
 The idea being that no other transactions could see the table (in any important way anyway..  couldn't SELECT from it,
forexample) since it was created in the same transaction that the data was loaded.  This would avoid having to rewrite
thetable to set the hint bits and to set the tuples as frozen after the data load.
 
 There's a question here is about if concurrent transactions in serializable or read isolated would be able to see the
newtable too early, because catalog lookups typically use SnapshotNow, and hence might see the new tuples when it
reallyshouldn't be able to.  It seems odd to me that it might be able to select from this new table which was committed
ina transaction which started after the current one though.
 
 Anyway, just a thought that I wanted to get out to hackers before I destroy the brain cells that it's stored in
tonight...:)
 
     Thanks,
    Stephen