After yesterday's speculation on season 5, Jackson was nice enough to give me some more specifics on what exactly is going on. On how the episode production pipeline is going he had this to say (emphasis mine):
Things are moving briskly over here at Venture Central/AstroBase/Titmouse. The first episode just shipped to Korea. But you're wrong about one thing--it doesn't take nine months to animate overseas. Nine months is more like the time it takes to complete an episode from initial design to final edit, so it includes pre-production. Actually, it's more like ten months, since we began design on the first episode the first week of the new year, and we'll be delivering it to the network in early October. According to our schedule--and assuming we keep to it--all ten episodes will be completed and delivered by the end of January. Which is roughly when we're supposed to premiere the fifth season.
So, new Venture Bros. to kick off the new year? Sounds like a plan! Jackson also noted that he and Doc likely will be attending all three conventions this summer (SDCC, Dragon*Con and NYCC) and they promise to show off whatever they have ready at the time. SDCC comes a little too early in production so they might not have any stuff to show off just yet, but Dragon*Con and NYCC will "maybe kinda" have some sort of trailer.
And finally, he promises that he still loves you all and will start posting art and whatever else on his LiveJournal fairly soon. Thanks, Jackson!