Addresses all the issues of the first and a bit more besides
The storyline is just as good this time around, picking up right from the moment AC1 left off. It's one of those games that while still is a good game, won't make much sense storyline wise if you haven't played the first. There also isn't much of an in-game tutorial, as it is assumed you have played the first, and the controls are similar. All in all, it is recommended you play the first before picking up this title, or at least get to grips with the storyline on wikipedia beforehand.
The repetitive nature of the first was its main criticism, and has been substantially addressed. The pointless flag collection has been replaced with feathers, and has at least been given a litte context in the storyline. The weak side missions from the first have been replaced with races, beating up cheating husbands, and assassination contracts, and a few moer things besides. The assassination contracts are a nice addition, letting the player carry out numerous assassination missions, which some felt was a bit lacking from the first, the lack of actual assassinations to do. Each one is individually titled and has its place in the storyline, which is a nice touch, though by no means essential for the main storyline completion.
The player has the ability to earn money in this addition, which can be earnt by fulfilling contracts, doing storyline missions and finding various treasure chests scattered through the whole of Italy. These can be spent on various weapons, armour, different outfits, throwing knives, paintings for your villa etc. The villa is an excellent addition, allowing the player to take income from a family villa by increasing it's value through renovations and adding paintings from art merchants. While this is a fun mechanic, you rarely feel that gathering enough funds or improving your villa is difficult, and seemingly all too soon you simply have nothing left to spend your money in.
The same can also be said of combat, whilst although being incredibly sastisfying timing counter attacks to then switch to another camera angle to watch Ezio the protagonist rip an enemy to shreds; it rarely challenges the player, where taking on 30 enemies at once is not an unrealistic prospect and finding a battle so difficult as to the point of being desyncronised (dying in AC2 terms) is a rare occurance.
Overall, this is a great game which will easily see you put in >10 hours at least. It's few weaknesses are more then offset by its at times magnificant qualities. The free running mechanic never gets old, and will keep you entertained for quite some time.
Personally I feel all the bad points are made up for the 5 second cutscene interval where a Mario will introduce himself with the (surely copyrighted?!) line 'It's a me, Mario!'