With increasing difficulty would purchasing a BFL Jalapeño even be worth it?
In terms of cost/performance, they rank quite well. So if you could actually get them and they actually worked as advertised, sure they'd be great. Which is why everyone hasn't requested a refund, just in case they ship.
However, it's likely 4-6 months before you get the unit, maybe longer. At that timeframe, it's not worth it. There are better options available right now.
https://bitcointalk.org/index.php?topic=192916.0Buys you some batch #3 ASIC chips. 16 for 5Gh/s or 64 for 19 Gh/s.
You should be able to get those built into a mining rig (through steamboat or someone else) within 10-12 weeks. If you were looking to get into ASIC mining, that's probably what I'd do.