I'm not current at all, I have no idea how many now go to the hall I used to go to, but I get the impression it's less than it used to be.
I think JWs fall in to several categories
1) People that are born in - I reckon at least 60% of these will stop going once they realise what it's about (out of three kids my mother had - none of us go now).
2) Vulnerable people, people who have lost someone and cling to the resurrection hope like a comfort blanket, or people who have been abused or are emotionally fragile; people who 'feel the love'; people who 'need' something in their life.
3) Elderly people, people who have always gone because, well, they've always gone.
The number of born ins who stop going will increase due to being members of the google generation - no matter how hard the elders condemn the internet, the kids are gonna google and a brain worm will get in.
In developed countries the numbers will fall due to the information on the interweb. If there will be an increase it will be in undeveloped countries where the internet isn't readily accessible, but this causes an issue as their ability to contribute is waaaay less than those from developed countries.
I think we'll see a lot of the printing stop, it's an anachorism in this day and age. The WTS will send the info out in PDFs and get the publishers to print it out themselves, or use the ipads and offer to email a copy to the householder.
In essence the WTS will downsize its operation due to its dwindling cashflow.