This post will be mostly a statement and little bit a question:
For those of you that didn't know the latest Nevada build or open Solaris supports iSCSI targets. It looks like it maybe a bit more complete than the IETD project this implementation. This implementation supports RESERVE/RELEASE which I'm told is very important when using vmotion to prevent data corruption.
I must say setting up the Solaris side is very easy.
iscsitadm create target -z 10g -b /export/home/test test
That creates a 10gb target and dump the container of the block device in /export/home/test and test is mearely a friendly name it creates the rest of the iqn number. I tested it using my M$ iSCSI initiator all is good I can see my LUNs.
Then I goto setup the ESX side. I enable the initiator. I disable the firewall rule to allow iSCSI out of the server (doh I forgot that one originally). I add my iSCSI server to the config. I rescan the initiator for LUNs which then causes iscsitgtd to die and all my LUNs go away 
Its easy to fix:
iscsitadm create target -b /export/home/test test
Then my LUNs are back. Has anyone been successful in getting ESX to attach to an iSCSI target on Open Solaris? I'm not doing anything fancy at all no encryption, no authenication.
I have also posted over at the iscsitgtd porject on opensolaris.org seeing if I get any hits.
tb
For what is worth, I’ve got the OpenSolaris iSCSI Target to work and this is what fired my imagination: http://blogs.sun.com/simonredmill/entry/nevada_b54_iscsi_target_vmware
I'm currently using build 57 and ESX 3.0.1 and I can’t remember doing any fancy tricks to get it working.
I set up a standard install of OpenSolaris (build 57) and created a ZFS pool from which I created a zvol which I made an iSCSI target (build 57 comes with the shareiscsi=on switch in zfs, most handy!). Admittedly, I haven't done anything fancy like target portal group settings etc. But I was able to point my ESX servers (yes plural!) at the OpenSolaris box. As you did, I enabled the opening of the firewall for the iSCSI initiator, enabled the iSCSI software initiator, pointed it to my OpenSolaris box, connected to the target and formatted it as a VMFS datastore.
Even better, I am able to do the same with my second ESX server and have the OpenSolaris box as a shared storage device (can you tell where this is going...) Creating a virtual server on the first ESX box and storing it on the VMFS datastore held by the OpenSolaris box, I was then (through my VirtualCenter server) able to Successfully Vmotion the virtual server to the second ESX box, a process taking less than 20 seconds and suffering no dropped/lost packets along the way. The virtual server continues to function merrily on either server and is this poor mans answer to a SAN based shared storage 
The only problems I've had have been when I tried to deploy a virtual server from a template held elsewhere to the OpenSolaris datastore. This would indeed crash my iscsitgtd and I would have to go through the laborious process of restarting the service on the OpenSolaris box and 'messing about' with the iSCSI initiator on the ESX boxes (e.g. rediscovering the OpenSolaris iSCSI target, rescanning etc. etc.) But I can usually get things back.
I'm holding out for build 60 of Solaris Express Community Edition to deploy on my current build 57 box to see if it’s any more stable. From a production point of view, it still seems a bit 'flaky' but I am totally impressed and in awe of what can be accomplished with a dollop of perseverance and a bit of redundant kit.
My vision of an HP based OpenSolaris iSCSI Target, 'floating' on ZFS (and all the wonderful features that offers) and accessed by my Virtual Infrastructure setup may indeed be through rose tinted glasses. But surely the cleaver guys out there can get it working, and guys like me can set it up and to do the cool Virtual Infrastructure things. The thought of ZFS, iSCSI target and Virtual Infrastructure, well, isn't it the best thing ever??