Removing an accidentally incorrect vdev from a ZFS pool

Hello everyone,
I've been using ZFS on -CURRENT for a few weeks now with quite decent 
results.  I'm really glad that this apparently awesome filesystem is 
available, and want to register my thanks for everyone who put work into 
it :)

That being said, I've just run into a little snag.  I wanted to extend 
my zpool from 3 drives to 6 drives.

My first hope was that I could automagically extend the RAIDZ.  My hope 
was to extend the vdev to be a raidz1 with 6 devices, and then restripe 
it to raidz2.  That would have been pretty neat, and a great way to 
manage drives.  After reading the man pages and not finding that 
functionality, I found many mailing list posts with everyone chatting 
about exactly that.  I hope the functionality finds its way into 7.0. 
I'd add it myself, but I tried to read the ZFS code and a good 
percentage off it flew over my non-filesystem-geek programmer's head :)

So then I settled on the next-best thing - adding another raidz1 vdev 
with the three new drives.  Not quite as flexible, but still adequate.

   I checked the dmesg to find my drives - ad12, ad16, ad19.  I ran
sudo zpool add universe raidz1 ad12 ad16 ad19, and then checked zfs list 
to find my brand new double-sized zfs.... huh?  It only grew by 40G? 
That's strange.  Maybe the zpool grew... nope.  About here is where I 
started to panic a bit.  Checked the dmesg... oops!  it was ad18, not 19...

Anyway, my questions now are:
Am I correct in concluding there is no way to reshape a raidz1 to a 
raidz2?  Is this functionality planned?

I now need to remove this broken vdev from my array.  I haven't added 
any data, so there shouldn't even be any data at all on it.  However all 
the remove/delete options to zpool seem to exclusively work on mirrors 
and hot spares.  I really need to get this vdev off the zfs - it's 
entirely useless.  How can I do that?  I've already taken out the 
accidental drive - I want to try to recover the old filesystem off of 
it.  Lucky it wasn't too important, though it'd be nice to have.  Now i 
have an array stuck permanently degraded.

On a related note, perhaps zpool should do a bit of sanity checking.  I 
know the Linux md tools require you to 'force' array creation if the 
drives differ by +/- 5% or thereabouts.  I just created a 400G/400G/40G 
raidz, which is a totally stupid array layout.  Maybe it should try to 
catch it.  (Yes, I should have caught it, but it's easy to miss the 
extra digit when you see 4xxxxx and 4xxxx next to each other, especially 
when they don't line up)

Thank you so much for any advice anyone can offer!

Steven Schlansker