The cinematic approach comes to level 5.
As I wrote on Twitter while rolling up five new alts over the last week, the new starter zones have a very "My Cataclysm, Let Me Show You It" feel to them. NPC dialog (which the player may or may not be required to stay and watch) does its best to point out exactly what it is about the world your new character has entered that would not have been true two weeks ago. In some ways, this experience seems more tailored as a sales pitch to returning vets (of which there are many, at least on the blogosphere) than actual newbies (who won't know what the story was before).
At the same time, Blizzard's efforts for simplified skill/spell progression have left those early levels surprisingly boring from a gameplay perspective. New casters literally spend two levels mashing a single button ad naseum because they only have the one spell. Combat may be balanced for characters who aren't carrying a heirloom arsenal, in the sense that the mobs pose the correct level of challenge level to players, but it is designed to lack the tactical depth that comes with more situational spells that the character will gain later (sometimes much later) in life. This may help newbies learn the basics, but it paradoxically makes the early levels feel trivial for the vets that the story appears to be aimed at.
(Meanwhile, I almost regret my decision to pursue as many heirlooms as I did. I put a throwaway Night Elf Mage on my Horde server, where I "only" had access to heirloom shoulders and an enchanted staff, because I only have so many slots to spare on my main server with my main arsenal. The character proceeded to one-shot his way through much of Teldrassil.)
I thought my twink gear was OP, but at least my arms aren't wings.
Upside in the Shattering
The real upside to the revamp comes at the game's mid-levels. Players who are looking to burn through to max level ASAP to join the group game can rest assured that they will no longer be forced to run all the way across a zone just to turn in a FedEx quest that doesn't award enough exp to justify the largely non-interactive travel time. Players who actually enjoy the "tourist" solo game offered in the two expansions can now expect the same types of vehicles, scripted events, and convenient travel that are found in the game's more recent content; you're probably going to run out of races and classes that you haven't already played before you run out of content.
(Alternately, you can go back on a flying mount after Cataclysm to blaze through the new stuff on a level 60+ character just to see the storylines.)
All that said, Cataclysm does not (and indeed should not) fundamentally change the game experience itself. Players who complained that the last expansion was too much of an "on rails" experience really don't have any grounds to claim shock when an expansion that promised to make the old world like Northrend delivered on its word. Though there definitely is some neat new content here, the re-roll experience is designed to go quickly, and players who weren't alt-o-holics before probably aren't such completionists that they're going to feel compelled to re-roll multiple times.
If anything, my biggest concern with the revamp is whether Blizzard has planned for the next Cataclysm. The current story is very strongly rooted in a sense of "this happened RIGHT after Wrath". This is really neat now, but in a few years it may seem as dated as the journey into a Northrend still ruled by Arthas is today. Problems for another time I suppose.