Huh? What's the difference? Usually 10-20% of all shares become public. Who where the rest of the shares are? It would only be a concern if EMC was not doing well - we would be in danger of a secondary offering, which would increase the number of shares on the market, potentially driving down price. However, it's not the case, EMC has tons of cash, and any money from the IPO went back to VMW, i believe to pay down debt and to build a new headquarters.
Honestly look at the chart. There aren't too many pullback opportunities on this one. I just recently bought in on a couple 2% pull backs. First to 74, then to 77. You might get a drop back down to 86 or so but I wouldn't think it would go lower than that.
I kept buying and selling, locking in my gains and fearing it may drop. However, I keep having to buy higher than I previously sold :-( Maybe should just have stuck to it from the beginning $50. My point is any time is a good entry point, the sooner the better. You could always set a sell stop :-)