I'm really bummed at this!

Hsu has abandoned the cylinder form they popularized and switched to making only powered box subs. The TN-1225 was discontinued last year, and they recently announced the TN-1220 has been axed, too.
I don't know about you guys, but I'll never use a powered sub in my main rig. A sub enclosure is a lousy place to stick an amp! There's extra heat and vibration to contend with which is not good for an amp. Think about it for a moment- how long do most vendors warrant the driver? And how long will they warrant the amp? Now you're starting to see.
This pretty much leaves Adire, SVS & VMPS as the only makers of passives I can think of, off the top of my head. Regardless of the performance of the boxes, I think it's a damn shame we no longer have the slender, space saving tubes.