I thought I'd throw this thread up to talk about my experiences with the tool...maybe it will be helpful to Clem or someone else, I don't know. I certainly invite anyone else who tried the tool (or is thinking of trying the tool) to post their experiences.
To start I burned a copy of the ISO to disc. I HIGHLY RECOMMEND that you do this. If you can't burn a disc for some reason (certainly possible if you're thinking of using the tool) then you might want to stick with Elyssa until you can get your hands on a Mint 6 disc.
I choose to use the tool as I was hoping for an Ubuntu-like experience where I could easily update my OS version without having to format (and thus have to mess with any of my documents). For the record, I'm using the following
Dell Vostro 1400
Intel Core 2 Duo T8100 (I think?, something like that)
3 GB DDR2 SD-RAM
160GB 7200 RPM HDD
Nvidia GeForce 8400M
So I grabbed the tool off of Synaptic as per the blog post. The tool was easy enough to use and behavied similarly to Ubuntu's upgrader. After the process was complete, I went to reboot per instructions. I hit grub and had the newer kernel listed alongside my own kernel. Picked the new kernel AAAAND I hit the command line =( It showed the splash screen loading Mint up but then went right to the command line.
Now, unfortunately, I am a big noob when it comes to the command line. I use Ubuntu and Mint as my Linux distros of choices because they allow me to avoid the command line. Anyway, I did sudo shutdown and ended up getting all kinds of weird garbage (including the splashscreen which would move slightly when I hit the enter key?). Well, after rebooting, I tried the old kernel and got the same thing.
At this point I decided to put in the LiveCD (which I'm on now). I'm going to probably just install via the LiveCD (which is what I should have done in the first place)
So, for the most part, Clem was right, the LiveCD is the way to go. Personally I'd love to see the tool start to work on the level of Ubuntu (again, I am a relative noob even though I've been using Linux for awhile so hopefully those who are more knowledgable will have no problems with the tool). Thanks for making the tool available, I hope it gets some refinements. I wouldn't mind trying it again when Mint 7 shows up but I will absolutely be sure to have the ISO on a disc before I try it.