There's of course the matter of 'inflation'. If new chips are injected into the system on a regular basis, one year from now, 1000 chips won't be worth what it is now today. Things that could be done to counteract this:

• Once a day (or week, or 10 days), a tally is made of all the chip counts. Points get awarded to the N people with the highest chip counts, and all chip counts are reset to 1000. Statistics could be created for people having the most points, and having scored the most points in the last D days (D=365 gives you a year).
• On a nightly or weekly bases, everyone who has more than Z chips will be deducted by Q%. This requires some tuning for acceptable values of Z and Q.
• "Glamour" tables, in which you can only participate after paying a significant amount of chips as house stake; but that only works if there's something to force players to participate at such tables. One way of 'forcing' people is to barr players having a large number of chips on "regular" tables if they haven't played at a "glamour" table in the last W days.

But these are just some wild ideas, I'd expect many people not liking them.