What type of preparation can and should be done in those days?
A very obvious area that needs substantial hours of work is limit mixed games (for the HORSE event). The danger though is that this could become a big black hole of time since there is just so much to learn. The law of diminishing returns will take effect at some point, but it is hard to predict if this happens after 50 hours, 100 hours, 200 hours....
i) studying the poker literature, with a particular focus on "7 card stud for Advanced Players" (no more reading fiction novels!)
ii) practice remembering other player's hands for stud games (both online and live; online for the convenience, but plenty of live practice is needed because of the additional need to remember your own hole cards)
iii) become very adept at calculating pot equity based on my outs vs. the number of exposed cards (an additional habit completely unnecessary in games with community cards, like hold'em)
iv) plenty of ring game experience with postgame analysis done on interesting hands (a Vegas trip might need to be thrown in to get some actual live experience in these types of games at non-trivial stakes)
Two other major areas related to stamina that will receive substantial time investment are: v) physical fitness training/healthly lifestyle and vi) practice concentrating for longer periods of time.
v) daily exercise (particularly cardio), better sleep habits (sufficient sleep at regular times), better diet (less fat and salt, more fruits and veggies), drinking more water, ginko biloba? (So long free radicals!)
vi) partake in lengthy (10-12 hour) live game sessions
I think (vi) is important because I've actually had very very little experience in playing live for prolonged periods of time, and the times that I have were plagued with plenty of terrible decisions in the later hours (e.g. both of my WPT events). Probably (v) will actually have a bigger effect, but somehow I think it will be good to practice (vi). (vi) could be started in a few weeks time to allow the benefits of (v) to kick in.
vii) more practice in deep stack NL tournaments, such as the Stars Deep stack tournaments. (this was an area that I talked about earlier in the year, but never followed through on) Additionally, I will continue to play supers for $10k events like FTP's Winners Choice or Interpoker's LOQ, with the intention of using the entry for WPT Mirage or WPT Mandalay Bay.
Another outlet for practice might be the $30 NLHE rebuys on Party. The number of chips in play becomes quite substantial due to the crazy first hour play, but also because of the rebuy bug abuse.
On a slightly different note, I've been reflecting a bit on how crazy things have been lately.
The last month or so has been quite a thrill ride in MTT/supers. For example, at some point in each event I have had at least $5k in real tournament equity in 6 different MTTs/supers and double this number with at least $1k of equity. This implies I was involved in a fair number of hands that had close to a 5 figure outcome. That is just sick. I don't know if I want to be able to become desensitized to such things, but I do know that I am very affected by these swings. I suppose I will either get used to it, or else become prematurally grey or bald or both.
In limit ring games, my swings were in the +/- 200BB ranges at some of the higher stakes I have played at ($10/$20->$15/$30 online and $20/$40->$40/$80 live). The difference was that these swings came over a longer period of time; hours or days, not seconds.