Oh, THAT issue again - separate TS for tables and indexes, never the twain shall meet. I think the latest understanding of that is it doesn't matter for the most part.
But, 1500 indexes? That seems like an awful lot, and too many can actually degrade performance. Are they all being used? v$object_usage view in 9i, turn monitoring on. I bet there are hundreds not being used.
Maybe they're all in the SYSTEM tablespace -- that'd be a pretty good reason for moving them.;)
Unless they belonged to SYS of course.
Or maybe they are locally partitioned indexes on a partitioned table, which is paritioned on the days in a year... who knows...