The Cavs were the best team of the regular season last year too. Didn't work well in the playoffs, did it? 
Cavs are overrated, they are still a bunch of roleplayers around LeBron. If they add a good player like Jamison they could get really dangerous, but even with a key addition like that, they are not the favorites to win a championship, so no need to panic, and even more now, since they still have the same team (LeBron + roleplayers).
Cavs lost in the Final 4 - because they could not defend Dwight Howard. Shaq solves that ... he can stand behind Howard and take advantage of Howards tiny legs (like Perk does).
The Cavs were a 60 win team last year, and are still - Orlando was just a nightmare matchup ... the Cavs have improved their ability to handle that.
The way they crushed LA on Xmas day says more about their hopes than anything else.
Cavs had the easier path to the ECF last year, starting with the ridiculous and going nowhere Pistons in the first round. Then they got lucky in the second round because the Hawks were depleted by various injuries to key players in all 4 games. Sure, they swept them, but the series was closer than we tend to remember it, and it would have been a much tougher series for the Cavs had the Hawks been healthy.
It seems that they have improved against Orlando this season but don't forget that they played their first game against Orlando when Lewis was out (big factor), and that they won the second game in the 4th quarter, while Orlando did make a comeback after being down big. They lost in the 4th due to fatigue of the back to back, and Howard dominated Shaq so I don't see their problem as fixed (although I think Hedo was a big advantage for the Magic against the Cavs).
Also, these two games were on a back to back for the Magic while Cleveland had some rest the day before. And between the last 2 meetings remaining against Orlando, the Magic has yet another back to back game against Cleveland. The NBA is favoring Cleveland in their regular season matchups against Orlando.
The beatdown of the Lakers on Christmas Day means nothing (good game by the Cavs, too much complacency from the Lakers, move on), and the Cavs win against the Lakers in Cleveland neither, it's just regular season games. Sure, it's a boost of confidence for Cleveland and huge wins for the homecourt advantage race, but the Lakers still have better players and a better froncourt. If Gasol is still playing soft in the Finals, should these two teams meet, Cleveland would have the edge, but I just don't see Varejao and Shaq dominating Bynum and Gasol like they did in the regular season.
As of today the Cavs still are a bunch of role players coupled with the 2nd best player in the game. Not a recipe for success - in the regular season, yes, in the playoffs... not so much.