The keyboard icon seems to have been disabled when viewing PDFs now, so jumping to an arbitrary page number is definitely out now (I know it stopped working in 2.5, but I was hoping it was going to be re-enabled in 2.6).
If the iRex team is reading here
... please could we have some way to jump to an an arbitrary page?
Also, there still doesn't seem to be a way to go back after following a hyperlink in a PDF.
One other feature I'd love to see would be a way to jump to the first place in a document that contains a hyperlink ... my logic being that this would most likely be the start of the contents pages, which is a good place to be able to come back to when exploring reference material, which is what most of my documents are.