What is the best practice to choose WIs and create baseline?

Hi guys,

Our baselines (snapshots) were created directly in the stream (with the latest version of all files).
Now I'd like to choose some of the incoming activities and create a package (release) only with them. But I have some questions.

Scenario:
Implementation of tasks feature 1, feature 2 and feature 3.
These three tasks modify the same file web.xml, ok?

web.xml History:
http://www.brunobraga.com.br/img/jazz/rtc_print1.png

The last snapshot baseline-feature1 has the feature 1 only.

Need
So, I need to get baseline-feature1 and add the task feature 3 only, ok?
The task "feature 2" began to be developed first, but I dont want to add it to the package at this time.

Incomings
After I load baseline-feature1 I see that:
http://www.brunobraga.com.br/img/jazz/rtc_print2.png

Accepting feature 3:
http://www.brunobraga.com.br/img/jazz/rtc_print3.png

The feature 3 was implemented after feature 2 and accept it alone will create a "Pending Patch". Its ok. But the merge "Pending Patches" into workspace will create a new version of web.xml (with feature 1 and feature 3).

I think I need to do checkin of this new web.xml to add it into a new baseline. But if I do that, this version will be the last version of the repository and it will be propagated to the team. If the developers accept this incoming, the changes in web.xml for "feature 2" will be deleted.

So what is the policy / best practice to generate a baseline with some (sub-set) workitems completed?