I think several large species will go. We're currently living in the 6th mass extinction event (caused primarily by humans), but most haven't really noticed and they won't until things like rhinos, tigers, cheetahs, elephants start to go.
Sadly I don't think rhinos will make it, some sub species have already gone, others are too few in number to be robust enough to survive.
When I studied ecology at university, I read that cheetahs are no longer genetically diverse enough as a species to survive and that was 20 years ago. 
If bees go we're all fucked.
I think we'll see a return to deaths from infections due to antibiotic resistance. They were a remarkable discovery that have saved countless lives, but we've taken them for granted and squandered them for profit.
Between they're constant low level use in factory farming, to them being available to by over the counter in some countries and people demanding them for viruses and/or not completing the full course they're given, more and more are becoming useless.
So I think routine operations etc. will become much riskier for us all due to infections that we won't be able to treat.
Probably not in my lifetime but I think the grandchildren of current children will be astounded that at the thought of putting petrol/diesel in cars and having to drive them 