In the next DOTA 2 6.79 patch, Valve reworks dozens of existing heroes and introduces general fixes to known bugs.
On the DOTA 2 developer forums, a lengthy post goes into detail explaining tweaks to the overall game. When dead, Buybacks take 25% of the remaining respawn time and adds it to the player's spawn counter upon next death. Other changes involve a now random respawn time for Roshan, who will now spawn anywhere between eight and 11 minutes after death.
Some items, such as the Bottle, now cost players 50 extra gold to purchase. With the price increase, players also start with 625 gold rather than 603 gold. Other items, including Tangos, increased in price from 90 to 125, but will give players one extra charge.
With the 6.79 update, many heroes received some changes to abilities or base statistics. Just as an example, Outworld Devourer's base damage drops three points, where as Earthshaker's Fissure range increased by 100.
No word on the official release of the 6.79 patch, but expect the download in your Steam client in the near future.