Although I've now moved on to Vim, I used TextMate for a few years and I really liked it. It's a great editor to get started with. I loved the bundle support that lets you extend it and make it fit your specific needs well. I had done a lot of customization to improve my own workflow. It also has a good number of shortcuts that make editing more efficient if you get to know them well.
However, once I got serious about learning Vim, it became clear that there was no comparison. When I use TextMate I amazed at how much less efficient it is. I'm not happy about everything with Vim, I use MacVim which is nice but it doesn't look or feel as nice as TextMate or
Sublime Text 2.
There isn't any type of vim-mode it TextMate and I don't know if TM2 will make it possible for anyone to implement one. However, Sublime Text 2 (which is cross-platform, btw) just released vi-mode in its latest update and it looks pretty good. I tried it out and it looks tempting, but I've been sticking with Vim since I have so much customization there.
As programmers, editing code is what we do all day. I believe we should be as efficient as possible and use the best tools at our disposal, and I believe that Vim has the most potential for efficiency of all the options available — nothing else even comes close. I'm hopeful about Vim modes in other more modern editors, but for now I'm sticking with Vim.
If you've never tried Vim and you're serious about programming, I encourage you to give it a shot. Getting started is really difficult for a while, but it's totally worth it and I believe will pay off in the long run.