The amazing mamedevs have been working hard on the SH-3 and SH-4 processor recently. And while most of the work is geared towards Naomi/Atomiswave it does have some bearing on CAVE shooters as well. (In fact it's noted in this post that this lays some groundwork for CAVE games such as Ibara)
I've noticed that Under Defeat and Chaos Field do run now (have for a little bit) but run so slowly that it often takes 3-4 minutes to get to the start screen. This dynamic recompiler described in the above link may help that, but I doubt anything will be in a playable form for awhile. But then again, they've made great strides these last couple months...
This might be old news, but I noticed that Guru has Ketsui listed as dumped now, i have no idea how long it's status has been that...
This may fall under off-topic, wasn't sure. Please move if wrong!
