What you'd find? Even more platypus I suspect - or maybe opossum...
Since we're being all serious, I totally agree on all these points. At the Broad we sequenced 48 healthy individuals 2 months after having completed our Ebola sequencing. What turned up in all samples? You guessed it - Ebola.
It's amazing what a simple water control can tell you though and is definitely something that needs to be done every single time. Low input seems to be the main issue with contaminants cropping up - used to be Pseudomonas, the it was E. coli, then Bradyrhizobium (the ones causing colitis...), but now it seems to be some weird viruses. Changes all the time.
Being able to do in-field sequencing using disposable reagents and equipment would be a big leap forward. @ig299 has a Sequencing Tent, I want a Sequencing Truck!