More generally, why do you think Bayern are looking more impressive this season fella? Do you think they'll be able to sustain their performance levels this term?
As for why they're so impressive, I can't really add much to:
A big bench with quality - big hunger for success after two dry years - maybe a better team harmony (it seems like they grew together more) - some "talents" now really seem to have made the next step - they changed their system a little (better pressing, playing forward faster, more position changes)
Last season they had the somewhat one-dimensional threat of Gomez supplied by Ribery and Robben, with an out-of-sorts Muller playing the majority of games and Kroos playing in the hole when they needed to change things. Now they often have Shaqiri, Robben and Gomez waiting in the wings and that fierce competition has really driven the starting players on. Ribery has 22 goals and 29 assists in 56 league starts over the last three seasons so really he's been consistently doing it whenever fit, but it looks to me like he's relishing the (frequent) role of being the only individual in the attack. Muller has 7 goals and 5 assists after just 9 league starts this season, he had 7 goals and 8 assists from 33 league starts last season. He's on course for his best season yet. Mandzukic is 4 goals off his Bundesliga goals total last season from just 1/3 of the games, and could potentially hit 25+ for the first time in his career. Then you've got Pizarro (all-time top foreign scorer in Bundesliga) doing his bit with some crucial goals and assists.
Last season they could have won the league and CL double (and perhaps even the German Cup to make it a treble) if it wasn't for Robben losing form right at the worst time. That's not the sole reason for it but his penalty miss and subsequent open goal miss from a few yards out v Dortmund plus his performance in the CL final really did have a devastating impact on both trophy challenges. If Robben had scored both goals it would've been a Bayern win and left them joint on points with Dortmund with 4 games left. Now they have a big enough squad to rotate those under-performing. Robben still looks far from his best (particularly finishing-wise) so they can rotate him as they need to to help him and the team find their best form. In the mean-time it means Ribery can carry the individual threat while Kroos, Muller and Mandzuckic continue to play unselfish football and contribute in a big way to the quick, incisive short-passing game that has defined their season so far.
It's easy to forget that Bayern now have a young spine to their team. Neuer (26), Boateng (24), Badstuber (23), Alaba (20), Kroos (22) and Muller (23) will form the core of their team over the next 5 years or so, with Martinez (24) and Shaqiri (21) likely to come into the mix as well and the majority of them will be peaking around the same time. Dante (29) has come in and added some class to that defence, Schweinsteiger (28) has picked up his form again, Luiz Gustavo (25) has taken his game to another level and Ribery (29) has been destroying Bundesliga defences for years so they've still got that blend of experience/youth and skill/steel.
Basically they've just grown as a team. Heynckes has 1 year in the job and is beginning to create his team, the young players have had a year or two developing in this Bayern side, they've made some really smart additions to improve the squad and change their attacking style, key players have recovered their best form and they're hungry after missing out on the title in consecutive seasons for the first time since '96.
Last season it was their attack that let them down at the business end of last season but that definitely won't happen this year. I still think there's questions to be asked of their defence because there's always mistakes there in a relatively young back five, but they're well capable of going all the way in all competitions this year. This year and over the next few seasons, I believe. Germany's the country to pay attention to over the next few years with some really talented kids breaking through more and more each season and Bayern will be there to take advantage on a European scale.