Our biggest issue this year has been network switches - we ended up having to look for suitable devices across multiple vendors, as opposed to just sticking to our preferred choice - some couldn't provide even a rough ETA on components, let alone shipping dates. Planning was made more difficult by auto-generated ETAs being e-mailed out and then obviously being missed.
We've taken the position that unless stock is showing as available, then expect to be waiting a long time - anything being sent for order is likely to be months, or even over a year in some cases. We've basically stopped looking at ETAs at this point.
We're actually in the process of writing a blog post for our web site about this and our experiences as it's had a significant impact on some of our current projects.
