Do you think they'll still screen what they managed to shoot of Series 5?
Probably; I hadn't seen Series 4 so I don't know if it ended on a cliffhanger, but SJA stories tend to be stand-alones so if they managed to complete a couple of storylines I can't see why they wouldn't air them.
All that said, I saw one blog suggest no Series 5 episodes were made because of her illness, but that's not what I recall reading in the filming reports. We'll hear fairly soon. If they didn't end up filming any Series 5 episodes after all, the title of the Series 4 finale will be even more poignant.
AIUI three episodes were shot, then filming pushed back until May...
Watching Pyramids of Mars now for some random SJS goodness (and the late Michael Sheard as well, who I knew better)