So far I have concentrated on ruins as the primary type of adventure. This is perfectly normal as far as I'm concerned - the name of the game is Dungeons and Dragons after all (unless you're playing a retro-clone, but that's another matter...) The ruined cities and towns ravaged and abandoned 50 years ago during the Wars between the Empires and the Summoning can be treated as above-ground dungeons, with quite a few underground areas attached. The basic dungeon-crawl is still the same, except there is a chance of getting rained or snowed on. There are plenty of ruins and dungeons, for example around Teiglin. For a more conventional (underground) megadungeon, I would suggest Seaview Keep.
Wilderness adventures have been part of D&D since they were looked at in the Expert rulebook. Travelling to and from towns or ruins and dungeons is the simplest sort, but there is much more - exploring virgin territory, seeking out and fighting foes in the wilderness, looking for resources such as rare herbs or unusual animal products can all prompt adventurers to step out into the great outdoors. Currently the major wildernesses detailed so far are forests, hills and seas - the Shorgan Forest, the smaller patches dotted around Teiglin, the Saltwater Forest, the Godsblood Hills and the seas around the areas described which have not been detailed yet. I intend to add a wider variety of wilderness soon (swamps, deserts, proper mountain ranges).
Wars and battles are on the periphery of D&D - the combat in D&D rarely exceeds more than 20 on each side, but in the stories and backgrounds there are great and terrible battles, mighty armies tens of thousands strong and ravenous hordes of monsters brought together under diabolical leadership. In Kaelaross the most obvious clashes are between surviving humans (and demihumans) against the forces of Chaos that have poured out of the Chaos Portals. The borderlands of Teiglin are just such an area, as are the deity-named forts dotted around Ironmarket. Different military clashes are possible but not so obvious - the dwarves of the Confederacy of the Ten Peaks deciding to stamp their authority on the humans of Ironmarket, or the elves and centaurs of the Shorgan forest repelling an overzealous Teiglin army, or maybe Baron Delphinius of Tredgor decides to raise an army to overthrow King Thestor II of Teiglin.
Political Intrigue is another possibility which I want to leave open even if it is not high on my priorities. The rulers of Teiglin all have different agendas, as do the dwarves of the Confederacy of the Ten Peaks. The politics may not be at a national/regional level, but could be at a local level, at least for newer adventurers. Who will be on the town council? Who is the next captain of the Town Guard? Does somebody have leverage over that wealthy merchant? The intensity of the intrigue may have declined since the Empires and much of society collapsed, but it is still there if you look for it, and these days the stakes are often just as high.
Crime has only been touched on. Assuming that the PCs are on the side of Law and are fighting crime, the big bad guy here is probably the Red Hand. They are intended to be a cross between the mafia and the Illuminati - they have fingers in many criminal pies, but are quick to withdraw before any spotlight can be shone on them or any evidence point to them. I am currently looking at adding a large city that is suited more to thieves than to any other adventuring class.
If, however, the PCs intend to become criminals themselves, that is quite a different set of adventures. Of course, the Red Hand could still be involved - first trying to influence and control the PCs, or secondly as rivals who view the PCs as unwanted competition. The forces of Law will not tolerate the PCs' crimes, but the resources the law can use to stop the PCs will vary, particularly if greater threats from chaotic creatures detract from efforts to catch and stop the PCs.
Planar adventures are possible, but there is still much to be written about this on this blog. The Planes of Existence are accessible to those with powerful magic, either spells or items. The planes that have the most obvious impact on the material plane are the Planes of Chaos. These can be reached by stepping through a Chaos Portal, but reaching one is no easy feat in itself. The reasons for going through may be for exploration, to prevent a terrible scheme or to rescue somebody stranded on a plane.
Finally trade and diplomacy involves travelling around Kaelaross and making peaceful contact with other communities. This overlaps with both wilderness adventures and political intrigue. The shattered, isolated and besieged state of many human and demihuman areas makes this sort of adventure difficult but rewarding - bringing news of recent developments in Teiglin to Ironmarket or maybe demihuman clans in other regions could have interesting effects on the campaign. As I said before, as the blog progresses, I intend to add more regions.