Several of the stages in Super Smash Bros. Brawl are exact copies of stages from Super Smash Bros. Melee, carrying on a tradition started when Melee included three stages from the very first Super Smash Bros. game. However, I can't help but feel disappointed in how they went about bringing back past stages. Instead of simply re-using a handful of stages from Melee in their original form, I would have preferred it if the developers had completely remade stages using the improved graphical resources of the Wii and had kept more true to some of the stage traditions of the first two games. As it is, it feels like Brawl has abandoned too many of the classic stages of the previous games.
One big reason that I don't like the treatment of the Melee stages is that they feel far too cut off from most of the game. To start with, they are placed on a second stage-selection screen, which makes them harder to get to and remember than the new Brawl stages. Furthermore, none of the Melee stages appear in the games Classic or All-Star game modes. The older age of the appearance of the stages also contributes to their segregation from the rest of the game. The game designer's probably left the stages as they were because they wanted to retain a nostalgic quality from Melee for these stages. That unfortunately didn't work, because there are significant differences between the Melee stages in Brawl and their original incarnations in Melee itself, particularly in the real of stage boundaries and camera behavior. So instead of feeling nostalgic about these stages, I am constantly reminded about how they are only flawed emulations.
I think that it would have been much better if the developers had followed the other examples of how Melee converted stages from the original Super Smash Bros. game. Several stages in Melee were re-imagined or updated versions of stages from the first game, including Corneria, Brinstar, and Green Greens (three of the Melee stages in Brawl). Corneria in particular is a complete duplicate of the Sector Z stage from the first game; the only differences between the two is that Corneria has a different background and slightly updated graphics. Similarly, Brinstar is directly based on Planet Zebes, albeit with a modified platform layout and new interactive element (although the central gimmick, rising levels of lava, remains the same). Green Greens is directly based on the original Dream Land stage in that it features the classic Kirby boss Wispy Woods using wind to sow chaos on the battlefield. Furthermore, the Mushroom Kingdom stage in Melee uses a lot of the same design elements that defined a stage with the same name from the first game. So Super Smash Bros. Melee reimagined and updated stages more often than it simply re-issued them.
I think Brawl would have been better off if it had given the Melee stages this same treatment. Instead of emulating the Melee Corneria stage, inferior graphics and all, it could have updated the look of the stage based on the appearance of the Great Fox from Star Fox Assault, the most recent game it has been in. Brawl did do this for a few classic stages; Battlefield, Final Destination, Yoshi's Island, Pokemon Stadium 2, and Port Town Aero Dive are all re-imaginings or faithful recreations of previous stages using Brawls full graphical capabilities. Since the developers had the resources to create a massive single player adventure mode, there was no reason they couldn't have rebuilt the returning Melee stages completely.