You're a 100% right, though. The present value of using what is out now is better than waiting and waiting and waiting--especially if you're savvy enough to sell and upgrade at opportune intervals.
This is definitely my strategy from now on. I kept my 2010 MBP for, well, going on 3.5 years at this point and I regret it. I would have had a much better time selling and upgrading each year, even if I had to take a decent percentage loss each time. I'd have the same machine I have now (the 15 rMBP) and wouldn't have ended up spending any more money in that time period. More importantly I wouldn't have been stuck on Arrandale for over three years, so any potential loss I'd take on the sell/upgrade cycle would have been worth it to me. (Think about this: If I'd spent $800 to upgrade every year, and that seems like a pretty big resale loss, I'd still have only spent an additional $2400 to get to a Haswell rMBP... which is exactly what I did anyway, except I had to stick with an older machine the entire time).
To stick to the original topic, IMO we'll almost certainly see IGZO in MBPs next year. This has been the ongoing rumor for a while in fact (most reports about Apple and IGZO point to 2014). Barring any exceptional circumstances (yields on odd resolution panels or issues discovered with the current panels in the wild) I'd say IGZO and Broadwell will appear in the same machine in mid to late 2014. Intel's release timeline for Broadwell chips will be the actual deciding factor for how late in the year this refresh appears.
Haswell's low load optimizations with Broadwell's 30% full load power consumption drop and IGZO's better power efficiency will be an impressive combination to see. This hypothetical machine could be configured for major battery life gains at Haswell performance levels or potentially see major CPU performance gains at current generation battery life. Or something in between. This part's up to Apple, but either way the opportunities for gains are big when you put those three elements together.
Apple isn't known to be an early adopter, but if IGZO is as good as the early reports indicate they also won't be holding off on implementing it. We're seeing analysis of the IGZO panels Dell is using suggesting that their factory calibration is just as good as the current IPS panels Apple uses, while the panel is able to hit significantly higher brightness (~20% brighter). If these results are accurate I'd guess the only thing that held Apple back was that at the size, resolution, and ratio they wanted no panels would have been available in large quantities in time for launch.