They are running out of money. That's why they're scrambling with all the cost cutting measures recently. But I don't think they will ever really run out of money - not literally. What will happen is that they'll be forced to keep cutting costs until their expenses drop below their income.
This might mean that the organization as we know it today, will eventually cease to exist. It might wind up being just a skeleton of what it is today. Maybe just an office with a writing dept and an IT department and a few volunteers. All literature will be online. JWs worldwide will be encouraged to get touch devices to download and view Watchtower material. Elders will be made responsible to make printouts for publishers who cannot get access to a touch device. They may even institue mandatory tithing.