Hate to flog a dieing horse, but I ventured all the way into these forums JUST for this feature so here's my 2 cents...
1st, I would definitely rank this problem above "a little bit annoying" if perhaps not "highly annoying". Yes, it's easy enough to open the minimized window and see who wrote you but that's not the point. Doing so interrupts whatever you're doing and that makes it "quite annoying" <--- (new level to ponder)
Let's say you're at work, you have 3 or 4 contacts in a tabbed chat (very useful feature) that you definitely want to respond to if they write back. Maybe coworkers, your sick wife, I dunno, you get my point.
You also have a dozen other contacts who might write you that you will get back to AFTER you finish what you're doing.
Then someone writes you... The taskbar flashes and you spare a quick glance down from what you're doing to see if it's someone worth interrupting your workflow for. You see your co-worker's name (cuz he was the last one you were conversing with prior to minimizing) so you abandon your train of thought, click on the bar only to find... it's your annoying cousin who wants help with Company of Heroes strategies (great game btw). Boom, your workflow is interrupted.
Sure, it's only 1 more click but it's all about the flow. Under the old system (I was one of those who used the old Tabbed chat in 7.5 with ZERO problems) If I was engrossed in something, be it work, a game, watching a movie or whatever... a quick, 1/2 second glance at the taskbar was all it took and I could carry on uninterrupted. Now I have to draw my attention away, pause what I'm doing, move the mouse, click the button and THEN make the decision to read/respond or not. Repeat this process a dozen times when you're busy with something and see how annoying you find it! Sure I could just set my status to "appear offline" but that's not the point, there are many many situations where you would like to remain focused but are willing to stop for certain individuals.
As a previous poster suggested, the ideal solution is: When minimized, flash the last person to message you. When open, keep attention on the active tab.
Can we all agree this is the best FUNCTIONALLY? I realize it had problems in the last release, but it WAS working for many. So if we can all agree that is the best way it SHOULD work (from a feature point of view) than perhaps it is worth the effort to resolve the bugs some people experienced rather than cripple the feature.
This is easy for me to say, I'm not a programmer or investing time into developing Plus but regardless, the Tabbed Chat feature may be a deal breaker for me. As MS keeps adding features Plus has had for years, Plus has to stay one step ahead to remain useful. This is bugging me enough that I'm sticking with 7.5 for now, but that will only last so long until the next version of MSN has something interesting enough to force an upgrade.
Sorry for the length and thanks to the hardworking people who make Plus a reality. This is not a rant, just a suggestion that you might want to re-prioritize this "intentional bug".
Justarius