If you have the spare change, a decent understanding of Japanese, and either systems that can play games from other regions with little difficulty or a Japanese version of the system, I'd say go for it. There are still a lot of Japanese games that aren't translated and released in English (and many of those still aren't likely to be); plus, there's always the chance that an English re-release may change things (features, etc.) or leave them out, have considerable script changes, questionable voice acting, etc.
I've imported games for quite some time; it was easy to do with my SNES, TG-16, Genesis - and the GB/DS play import games without any need for modification. The more recent disc-based systems will require either a hardware mod or a full Japanese system, though.
(I used to frequent the Japanese game stores (including one that sold used Japanese games) in San Francisco, but I haven't been to those in a while, so I don't even know if they're still there.
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