That image above is my main character's bags and my bank when I first logged on to the beta servers. It's a chaotic mess, I know. At the time of that screenshot, I had 20 bag spaces free, and one spot in my bank. As for Void Storage, it's completely full on live. So how much bag space can you expect to get with just the Toy Box and Void Storage tabs available to play with? If there was anyone to test that out on, it was me and my admittedly insane collection.
The Toy Box tab, while really cool, is also not yet fully implemented. There are quite a few items in my bags that should probably be labeled as toys, but aren't just yet, like punching bags, the Puntable Marmot, the Goblin Weather Machine - Prototype 01-B from the Warcraft TCG, and several other vanity items from old world events. I suspect that trinket items like the Cannonball Runner won't be added to the Toy Box tab, which is unfortunate because although it's a trinket, it doesn't really do anything useful enough for anyone to seriously equip the thing.
Items with charges like the Path of Cenarius or Falling Flame are also not in the Toy Box tab, likely because they have limited charges and will disappear once completely used up. This isn't a huge issue, because there aren't exactly a lot of these items with charges out there. At the moment, the engineering Dimensional Rippers for Everlook and Area 52 are allowed to be shuffled into the Toy Box tab, but the Wormhole Generators for Northrend and Pandaria are not.
After filling my second Void Storage tab and clearing out junk items and the few Timeless Isle buff items I had lingering in my bags, I ended up with what you see above. For those counting along at home, I went from 21 bag and bank spaces free, to 169. The best part? I haven't even used the reagent tab in my bank yet. All reagents have always been shuffled off to my bank alt, simply because I never had the space for them on my main character. Now I do -- along with enough space for whatever else I want to collect and cram in my bags.
While we still don't have a tab for tabards, it almost doesn't really matter. With all the other space solutions, having some tabards in the bank isn't really going to put a huge dent in things. You should still have plenty of space kicking around even after squirreling tabards away, and once the Toy Box tab has outlying items added to it, there will be even more space to work with. I'll happily admit I'm an extreme case as far as collecting goes -- but if even if you're not a collector like me, the new storage options should open up plenty of storage space.