Again I'm late...have tried not to look at anyone else's yet, so I'm not cheating ;P Will be little Aussie centric I imagine...lets see!
Batting Category
Best Batsman - AB de Villiers
Best Youngster - Virat Kohli is still only 25, definitely a youngster, unfortunately for India's opposition
Most Improved Batsman - Steve Smith
Best Innings - Chris Gayle's 175 in the IPL, never seen anything like it. If we are talking about 'real' cricket, then probably MS Dhoni's 224 vs Australia at Chennai. Came in with the 1st Test at crucial stage and destroyed Nathan Lyon, put his stamp on the whole series and India never looked back.
Failure of the year - probably Johnny Bairstow who managed to keep getting bowled over and over again. Cook, Trott and Prior also have a lot to answer for.
Bowling Category
Best Bowler - probably still Dale Steyn. We are starting to take him for granted I'm afraid - great bowler!
Best Youngster - Southee and Boult for NZ. Pattinson will return.
Most Improved Bowler - Mitchell Johnson was already pretty good vs SL 12 months ago, but he deserves a mention.
Best Innings - Dale Steyn's 6/8 vs Pak or Mitch's 7/40 vs Eng
Failure of the year - Graeme Swann in Australia. Ishant Sharma wherever he went
Team Category
Best Team - South Africa are still pretty good, same with India
Most Improved Team - has to be Australia right now
Decline of the year - England, duh
Misc
Best Tournament/Series - the Aus-Ind ODI series was ridiculously entertaining. Couldn't work out whether it was awesome or whether I should be crying for cricket with because of the unnecessary shoehorning into the schedule and/or the stupendous amount of runs that were scored
Best match - The 1st Test of the Ashes at Trent Bridge. A see-sawing match with great performances and incidents. Siddle knocking over England early, Agar's unprecedented 98 (batting with Hughes, good trivia question right now), Bell and Broad's match saving partnership, Jimmy Anderson finishing off the Aussies with some high quality bowling. Haddin and Pattinson almost getting there, falling less than 20 short.
Most surprising/shocking incident - Stuart Broad edging to slip and not walking...