Who fans would like to keep and who they'd like to get and what's actually possible are two entirely different things.
The Lakers have $88.7M on the books next year for:
Kobe
Gasol
Bynum
MWP
Sessions
Blake
McRoberts
Hill
Eyenga
Goudelock and
Morris
including $4.5M for Sessions who can opt out, $3.6M for Hill who's an unrestricted free agent and team options on Bynum ($16.4M), Goudelock ($0.76M) and Morris ($0.93M). Bynum's option will be picked up, as will probably Goudelock and Morris. Sessions has said he'll opt out to test free agency, Hill will get bigger offers than the Lakers can make.
So the Lakers will likely have:
Kobe
Gasol
Bynum
MWP
Blake
McRoberts
Eyenga
Goudelock
Morris
for $80.5M, or about $10M over the luxury tax cap. Because they're more than $4M over the LT cap, the Lakers are also put at a disadvantage in the free agency market because they simply aren't permitted to offer as much to a player as can teams under the LT cap.
The new CBA really demands that you build a team through the draft, rather than free agency, and severely penalizes teams over the luxury tax cap, not only with the tax, but also by reducing what they can offer to free agents, as compared to teams under the LT cap and how many cap exceptions they get.
In any Pau trade you can look for players, salary reduction through expiring contracts and/or draft picks. If the Lakers use Pau to get a player, they probably try to get a starting PG (Sessions is likely gone). If you do that, you're left with:
Kobe
Bynum
MWP
new PG
McRoberts(?)
as your starting lineup, with Blake, Eyenga, Goudelock, Morris, and filler as your reserves.
If they trade Pau for expiring contracts and draft picks, you're left with:
Kobe
Bynum
MWP
Blake
McRoberts(?)
as your starting lineup, with Eyenga, Goudelock, Morris and filler as your reserves. Depending on who the expiring contract is, he may be a starter replacing Blake or McRoberts.
The Lakers have traded away their 2012 first round draft choice, and their first round draft choice in 2013 is either a top 14 choice (i.e., they don't make the playoffs) or the worst position out of the first round picks of Cleveland, Miami and Sacramento as a result of the Sessions trade. So rebuilding through the draft isn't too likely, unless, again, they can get a draft choice or two back as part of a Pau deal.
Trading Kobe (if he waived his no trade clause) forces you to bring back salary, and anyone taking Kobe's contract at his age isn't going to be sending DWill or DHoward back; you'll likely get a decent player and an expiring contract.
So far as I can see, given all of the above, I can see two courses of action:
(i) the Lakers patch the team around Bynum and Kobe for next year, trying to effect significant moves (if any) through a Pau trade, and then either talk Kobe into retiring after the 2012-13 season or amnestying him at that time, or
(ii) the Lakers blow it up now, amnesty Kobe, trade Pau for expirings and picks, write off 2012-13 and plan for 2013 and thereafter.
Given the need to keep fans in the seats, I'm guessing it'll be option (i).
In short, don't look for a championship run next year.