Provided it does what I need it to - yes. I can afford it. All I need is a new elegant UI (with some nice eye candy), iWork (with revamped Inkwell Tech), Full iTunes, Full Safari, Full Preview (to edit PDFs) and Full Mail. Along with loads of new iTunes extras and some new MobileMe features, of course, including BTMM over 3G so I can checkin with my iMac at work when I need to.
I helped my girlfriend pay for trips to Africa and India this year. Part of the agreement included me being allowed to make 2 big purchases without dirty looks. This will be #1. Always think ahead.