I have a, 8330 with OS 4.3. I went ahead and downloaded the PDF Reader, Repligo. I cannot view PDFS in email from Blackberry. But can hookup to a PC and download them. It works wonderfully. I f you have 4.5 which is probably standard now, you can read the PDFs from your email. It costs a small fee but it's worth it to me.
Yes! I have an 8330 with os 4.5.0.127 and sent myself a test email with a pdf attachment. It worked beautifully. You can view the pdf or, you can even convert it to text only. I have only had the phone for about 5 days now, and have not installed any apps for that so that worked essentially right out of the box.
I couldn't seem to get a straight answer from anyone. One of the reps for Sprint told me yes, tech support told me "not at this time", the manual said yes.