Data Access Layer returns DataTable - vb.net

Question

Please have a look at the following question, which i asked some time ago: Breaking BLL (Business Logic Layer) to BLL and DAL (Data Access Layer)
This approach (Data Transfer Object) seems to work well if I am returning one record from the data access layer i.e. getNameByID returns one record.
What happens if you have a Data Access Layer function called getName(), which returns many records e.g. thousands or millions to be processed in the Business Logic Layer? (it is a scheduled task). When this is required I am currently returning a DataTable (because data readers cannot outlive a connection in VB.NET 2008). However, this question and answer seems to negate this approach: Is returning DataTable or DataSet from DAL is wrong approach. Is this a poor approach?
I realise there are ORM tools like NHibernate, which I plan to use more for future projects. However, the data access code in my current project is already written by someone else but I want to refactor it as I go along.
Update
Here is some code (as suggested by Stephen Doggart):
Imports Microsoft.VisualBasic
Public Class PersonBLL
Private Name As String
Private Age As Integer
Dim objPersonDAL As New PersonDAL
Dim personList As List(Of Person)
'Option 2
Public Function getPersonByID() As List(Of Person)
personList = objPersonDAL.getPersonByID()
Return personList
End Function
Public Function ShowMessageBox(ByVal listPersonBLL As List(Of Person))
For Each p As Person In listPersonBLL
Me.Age = p.Age
Me.Name = p.Name
MsgBox(Me.Age)
MsgBox(Me.Name)
Next
End Function
End Class
Public Class PersonDAL
Private Name As String
Private Age As Integer
Public Function getPersonByID() As List(Of Person)
'Connect to database and get Person. Return a person object
Dim personList As List(Of Person) = New List(Of Person)
Dim p1 As New Person
p1.Name = "Ian"
p1.Age = 30
personList.Add(p1)
Dim p2 As New Person
p2.Name = "Steven"
p2.Age = 28
personList.Add(p2)
Dim p3 As New Person
p3.Name = "Sharon"
p3.Age = 29
personList.Add(p3)
Return (personList)
End Function
End Class
Public Class Person
Private _Name As String
Private _Age As Integer
Public Property Name() As String
Get
Return _Name
End Get
Set(ByVal value As String)
_Name = value
End Set
End Property
Public Property Age() As Integer
Get
Return _Age
End Get
Set(ByVal value As Integer)
_Age = value
End Set
End Property
End Class
Public Class Form1
Private Sub Form1_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
'If Environment.GetCommandLineArgs(0) = "Test" Then
'MsgBox("Test")
'End If
Dim p1 As PersonBLL = New PersonBLL
Dim p2 As List(Of Person) = p1.getPersonByID()
Dim p3 As PersonBLL = New PersonBLL
p3.ShowMessageBox(p2)
End Sub
End Class

Answer 1

Returning a DataTable isn't completely terrible--there's certainly worse ways of doing it--it's only partly terrible. But, who wants to eat partly terrible food unless they have no other option?
So, unless there's some reason why you need to use a DataTable, I would recommend sticking with custom DTO classes and just have your DAL return a list of those objects. For instance:
Public Function GetNames() As List(Of NameDto)
'...
End Function