I'm very sad to hear that Panic are discontinuing another app - I found out about Status Board too late, but have been a heavy user of Transmit for the last few months.
I can't fault a company for cutting products which aren't money makers - but the App Store needs to change so that apps like these become money makers. Is it a niche product? Yes. Is it rock solid and high quality? Definitely.
I won't stop using Transmit right away - I will look out for other products and if I find a good alternative I'll switch. I just hope whatever it is has Workflow integration like Transmit did.