Python-3000 discussion <http://mail.python.org/pipermail/python-
3000/2008-March/012753.html> did not reveal any opposition to the idea 
of batch processing of dict displays.  However, a compromise suggestion 
was made to  limit batches to 256 items 
<http://mail.python.org/pipermail/python-3000/2008-March/012829.html>.   
I don't think this type of micro-optimization belongs to the core.  A 
rare application that would benefit from limited size batch processing 
can do so explicitly using dict.update.

See also relevant discussion at issue2292 (starting at msg65111).

I believe this issue can be reopen.  I will submit documentation patch 
if the change is accepted in principle.