I am considering leaving NW Silver elite for DL or CO, as NW is not really a carrier on the routes i would be travelling next year.do u guys know much about the transfer process of either DL or CO.

You can't transfer your miles or status to them. The only transfer I'm aware of is from NW WP to KL/AF Flying Blue if you move out of the US/Canada region into Europe. In that case, they actually will transfer your miles and status to KLM's program.

You might be talking about a Status Match. Not actually transferring mileage balance but rather matching your NW status to Silver status in the new program.

You're unlikely to get a status match from NW, by either CO or DL. That's because NW, DL, and CO are all partners in Skyteam. Beyond that, CO has a very close relationship with NW, and DL has a codeshare marketing agreement with NW beyond the regular Skyteam partnership. So there are informal or perhaps even formal "anti-poaching" rules against them going after each other's elites.

If you will be flying CO or DL, your NW status still counts anyway for boarding, standby, and check-in perks as well as RDM bonuses. On CO you'll still be eligible from complimentary domestic upgrades from your NW status. Your CO and DL flights will still count to re-qualify as NW elite.

So you might be better off just staying with NW even if you mostly fly DL and CO. NW is the only one of those three programs where all the following apply for a Silver:
1) Get 50% elite RDM bonus on all Skyteam airlines (except Delta which only gives 25% bonus to their own and anyone else's silvers.)
AND
2) Get full EQMs on all deep discount fares (except Continental's flights at 50% EQM)

If you switch to DL's program, you'll only get 25% RDM bonuses on any Skyteam airline, because Delta's limitation will apply to all airlines.

If you switch to CO's program, you'll only get 50% of the EQMs on all Skyteam deep discount fares, except for CO flights and then only if purchased on continental.com. If you stay in NW, you'll only get 50% on CO deep discount but you'll get 100% EQMs on deep discount fares on everybody else.

So if you plan to fly a mix of CO, DL, and NW, I think NW is the best program. Only if you plan to fly primarily (about 80%?) DL should you switch to DL IMHO. Likewise only if you plan to fly primarily CO should you switch to CO.

Plus NW seems to have a lot more promos for getting extra RDM's, a better award booking website, and in my experience better saver award availability than either CO or DL.

If you're dropping NW entirely and almost always flying just one of the others, then yes, maybe switching makes sense. You probably won't get a status match but if you can spin a really good story as to why you are switching exclusively to them, maybe they'll make an exception.

Being realistic, plan on starting in CO or DL without any status if you decide to switch.

Some people have reported no success in matches/challenges to a US-based ST airline based on elite status on another domestic ST airline--e.g., CO will refuse to do a status match based on a 'no poaching' agreement. Others have reported success, though, so it's worth a try. Check out the "Status Match Master Thread" in the MilesBuzz! forum for details on how to ask any airline for a match.

If DL/CO won't match NW for you, another option (but more $), would be to do a gold challenge on AA and then use AA Gold to status match to DL/CO... but really, unless you are flying DL all the time and are trying for upgrades (which as a lowest level elite...), there is no reason to do that (and waste a status match opportunity for lowest level elite when you already have status on that alliance). NW is the best program for redemption, earn rates and promos between the three.

Even easier would be to do a match to UA (probably free-no challenge) as a 2p and then try to get DL or CO to comp it. Of course, DL or CO may be reluctant to do so since you are unlikely to have many flown miles with UA.

Yeah, but by doing it that way, you also lose your one-time status match opportunity with UA. At least with the AA challenge, you don't lose any future status-match opportunities (except for CO/DL). But, in terms of no cost, that is the way to do it. But the better choice for OP is to stick with Worldperks, especially with a <50k miles per year of flights.

When NW first announced it bankruptcy I looked to another carrier to start building miles. A DL agent told me to write DL and ask them if they would match my WP miles ( I was WP Gold at the time ) and also to enclose a print-out of about 90 days worth of flights with my current mileage program. They responded saying that they couldn't actually match my miles but made it extremely easy to jump right into silver which I did. There after I continued to receive incentives to help build up the mileage. Good Luck !