Here's hoping someone gets back to this question. The iPad has become nearly unusable in a fleet of enterprise customers because of this.
Another way to word the problem: Multiple (way over 10) apps now open pdf files. if we view a pdf in safari and then want to "open in" ibooks or some other app, that option may not be available because of the 10 app limit in the "open in" dialogue. Apple should remove the 10 app limit and make this scrollable. I have hundreds of apps on my iPad and 10 is a laughably small number of apps to open pdfs. Here are a list of types of apps that I use that need to be able to open pdfs:
iBooks, e-signature apps, google docs apps, pdf annotation apps, pdf signature apps, travel apps
I did a count and I personally have over 25 of these apps that open pdfs. Therefore limiting the list to 10 is simply unacceptable for business customers & power users alike. PLEASE FIX THIS APPLE!