I do not think it will necessarily be a species threatening event, but make no mistake it is serious. The CDC in the US state that more people die from antibiotic resistant infections than die from breast and prostate cancer combined - around 90,000 per year.
http://scienceinsociety.northwestern.edu/content/articles/2012/tipping-point-threat-antibiotic-resistance
And whilst it is true that we are developing new drug discovery techniques etc, it is also true to say that all the major classes of antibiotics have been derived from bacteria themselves - and now we are pretty much down to one class of antibiotic, the carbapenems, to treat infections refractory to all the others. Even here there is some anecdotal evidence to suggest that some bacteria are beginning to develop resistance.
Pharma companies tend to focus their research efforts into the more profitable areas, and antibiotics are not considered profitable. The future antibiotic pipeline is pretty dry right now. There was a golden period of antibiotic development in the immediate aftermath of WW2 and up to around the mid 60s, but then no new antibiotics were introduced until around 2000 or so.
When you look back at the pre-antibiotic age, some of the leading causes of death were infectious diseases - cholera, TB and the like. Now, sanitation, clean water and hygiene will help in that fight, but antibiotics played a very big part indeed.