Lost Soul on ENWorld wrote up a set of rules he's calling "Fiction First". It changes a lot more than just the battlemap, although at a quick glance it's still clearly 4e-related. There's a section in the playtest PDF on skill combat, which is potentially gridless. The other material might or might not be useful to you, depending on how far from 4e you want to drift.
There's a few things that Essentials changes if you use the rules from their version of the Adventurer's Vault. Naturally, we'll find out most of them when it comes out:
1) All items are classified as Common, Uncommon, or Rare. This supposedly will also include every existing PHB and AV item, with nearly all of them being classified as Common or Uncommon.
2) A Common item will be found 50% of the time, and is an item that they say 'you apply a stat change to your character sheet, and forget about the item until you replace it'. This includes things like a Belt of Vigor that increases your healing surge, or other items with no daily effects or other triggered things. They sell at 20% base value, and large enough cities will sell them to people.
3) An Uncommon item will be found the other 50% of the time, and is meant for the more complex items that have daily effects, or the like. A Power Jewel, which lets you recharge an Encounter power once per day, would most likely fit into this class. Uncommon items, when sold back, sell at 50% of their value. Uncommon items cannot be purchased without DM permission--and usually purchasing or finding one of your choice is something that creates an adventure, rather than being routine.
4) A Rare item will be found once per tier per character--if lucky. These are a higher class of items, with stronger effects than what current items do--the rarity restriction is meant to overcome the fact that they're noticeably more powerful than another item of their same level, and a character would likely hold onto it for several levels before begrudgingly letting it go. When sold, a Rare item gives back 100% of its value. Rare items cannot, and should not, be bought in stores, and finding one is the culmination of an adventure, or a very lucky happenstance.
5) Daily magic item uses are out the window, as now you have Uncommon items being the items that would use them, and the DM now has control of how little--or how much--he wants to give the players that ability. This does, of course, nerf certain classes (Artificer) if this is used.
Best Answer
There are actually quite a few of them; Wizards of the Coast has been steadily tweaking and updating the system once every three months or so for a few years now. The errata PDFs can be found at the D&D web site at this link. You want the "Compiled Rules Update."