The Hounds simply cannot keep themselves together. This sounds worse than it is, and I intended it to. The party isn't coming apart at the seams... no, far from it. What's been happening is damned simple to explain but hard to cope with as a group: they've been splitting the party. Normally, this is the DM's nightmare. Running two, three, or four simultaneous games of D&D takes much more than running them consecutively. Keeping timelines straight is a headache. But the Hounds have something on their side that makes it slightly less troublesome: they're splitting the party, not to explore two locations at once or anything like that, but because certain characters are not in commission. While armor is repaired and the fighter doesn't want to go out, while the mage researches months worth of magic... these are times when the other players get antsy and determine that those long periods of interstitial time will not go to waste.
The solution, it turns out, was both mentioned here on this blog (although in the context of what to do in the case of character death) and also thought of by Danny some time last week, and its a solution that I was aware of but had been waiting (foolishly) for ~level 9 to implement. That solution is: play hirelings. When your character is tied down with research, play your character's proxy. Now, Nauraainen the Laughing Dragon may only be level 5, but he does devote a great deal of time to spell research—three months in this last go. To me, that signifies a good time to begin training an apprentice, simply because of the long periods of inactivity represented in game time. Narratively, perhaps, it is not the best solution... how are you teaching the child while you're working, for example?
Whether apprentice or not, the solution is clearly to play new characters in the form of hirelings (though in the situation of an apprentice it would be more like a henchman, I'd wager) who can adventure-in-proxy for the PCs. Of course, this opens up a whole host of strange problems (trading money and gear, etc.) However, that being said, those problems are preferable to having players sit out for several sessions which amounts, more or less, to punishing them for researching spells, having weapons made, or getting armor completed.
It's similar to what I imagine people USED to do before 2e, and also to the idea of the Character Tree from Dark Sun. In fact, I find that modeling it a bit on the Dark Sun notion will suit me perfectly, though it will need to be modified to account for the fact that the characters are not COMPLETELY separate but are instead linked by shared interests. A difficult juggling act for players, perhaps, but one that keeps them in the game and playing while also maintaining the verisimilitude of spell research, armor maintenance, NWP learning, etc.