Is there anything “dangerously” outdated from this WP Theme Creation Tutorial?

Hi everyone,

I am interested in creating WordPress themes. I stumbled upon this excellent, step-by-step guide:

http://www.wpdesigner.com/2007/02/19/so-you-want-to-create-wordpress-themes-huh/

My question is, can someone who knows a great deal about WP take a 5 minute glance at the tutorial and let me know if it’s “safe” to follow it’s lessons. I ask because it’s several years old now, and I’m curious if there are any huge security concerns with any of its methods.

I followed it and I learned a great deal! In fact, I created the tutorial theme on a brand new 2.9.1 install of WP, and everything worked perfectly.

Basically, has every function/code taught in that tutorial been replaced with something new during the last few years? Or would a blog using a theme from that tutorial be as safe as the latest default Kubrick?

Can anyone recommend any other excellent, but more recent, tutorials that are as simple and in-depth as this one?

Any and all help is greatly appreciated!