Work in Progres
Edirol FA-101 Firewire Audio Interface

The FA-101 has the highest specs available to support your most demanding applications. You get 24-bit, 192kHz simultaneous recording and playback in a compact 1U half-rack unit, with all the headroom you need.
Web: http://www.roland.com/products/en/FA-101/index.html
Specs
Supports up to 24 bit, 192 kHz Compatible with Mac OS X standard driver Two independent, on board mic pre-amps Capable of full duplex recording and playback on 10 independent channels Bus powered and durable metal construction for mobile applications Lots of ins and outs to support a wide range of recording and gigging applications
Comments:
I'm quite happy with this unit. It has been totally reliable. I get 3ms latency on 152 samples as reported by Reaper.
Roland VG-99

A Milestone in Guitar Modeling and Performance Technology Features
Web: http://www.rolandus.com/products/productdetails.aspx?ObjectId=849
Features:
Dual modeling engines New COSMŽ electric, acoustic and even bass guitar models New synth waves such as the famous GR-300 Guitar to MIDI converter for direct connection to keyboards, sound modules, soft synths, etc Supports USB audio and MIDI for easy digital recording and sequencing Dual GT-Pro-class effects processor enables unequaled flexible tone creation Advanced performance controls, including D BEAM, V-LINK and Ribbon Controller Simple and intuitive knob-based interface and new design support live performance Graphical Editor software included to support sophisticated sound making Versatile I/O, including USB, S/PDIF and XLR
Software Editor:

Comments:
I actually purchased this unit back in March and I have still not received it. Yes, it has been on backorder. The reality though is that apparently Roland has not shipped them out. Either they found some bugs or they are really trying to drum up demand. If the latter is the case , it is working.
Update:
finally , got the VG-99, truly an impressive unit. Overall, intuitive but I can tell its going to take sometime to be able to fully maximize its potential. I'll blog about my experiences later.
-- Charles