I don't know whether this will be an item to be addressed by slony, but 
I think it's worth mentioning: The default keys added by TABLE ADD KEY 
seem to be constrained by the length of the table name.

I'm getting this error:

<stdin>:7: PGRES_FATAL_ERROR select "_slony".setAddTable(1, 7499, 
'public.really_long_name_for_a_postgres_table_1', 
'really_long_name_for_a_postgres_table_1__Slony-I_slony_rowID_ke', 
'public.really_long_name_for_a_postgres_table_1');  - ERROR:  Slony-I: 
setAddTable(): table public.really_long_name_for_a_postgres_table_1 has 
no index 
really_long_name_for_a_postgres_table_1__Slony-I_slony_rowID_ke
CONTEXT:  PL/pgSQL function "setaddtable" line 37 at perform

Even though TABLE ADD KEY is recommended only as a last resort, this 
could be a severely limiting factor for installations with long table 
names that can't add UNIQUE NOT NULL constraints to their existing 
tables.

-tfo