that is a great point if they don't cap gold, however gold and real cash can be exchanged, then in theory there is no cap, and in theory every item will have a cash value uncapped because, gold=cash has an exchange rate. this is all really interesting. Because its almost like speculation of building a new currency, a new nation, a new country!
And its interesting to speculate which direction Blizz takes when they do see that happening? Will they tighten up their control and grip and install a Gold cap also? Or maybe the opposite and free up the market and let the players have it their way and increase the real cash cap to $1000? This is all really interesting to speculate.
But I don't think its a stretch, I do think the safe bet is changes will be made, if you played any blizz games, you know they are constantly altering and manipulating every little detail of the games they make.
Diablofans.com also posted a nice little calculator if you'd rather that.
http://www.diablofans.com/news/1188-...os-blue-posts/